Well, here is the my final ranking of episodes from the first 20 Seasons.
1/10 - Worst:
441. The Boys of Bummer (s18e18)
440. My Big Fat Geek Wedding (s15e17)
439. Little Big Girl (s18e12)
438. Homer Simpson in: Kidney Trouble (s10e08)
437. Co-Dependent's Day (s15e15)
436. Bart-Mangled Banner (s15e21)
435. Half-Decent Proposal (s13e10)
434. The Father, the Son and the Holy Guest Star (s16e21)
433. Brawl in the Family (s13e17)
432. Coming to Homerica (s20e21)
431. Rome-old and Juli-eh (s18e15)
430. Helter Shelter (s14e05)
429. Regarding Margie (s17e20)
428. Milhouse of Sand and Fog (s17e03)
427. Catch 'Em if You Can (s15e18)
426. It's a Mad, Mad, Mad, Mad Marge (s11e21)
425. Miracle on Evergreen Terrace (s09e10)
424. The Sweetest Apu (s13e19)
2/10 - Hate:
423. Pygmoelion (s11e16)
422. Husbands and Knives (s19e07)
421. Double, Double, Boy in Trouble (s20e03)
420. The Frying Game (s13e21)
419. Homer of Seville (s19e02)
418. The Regina Monologues (s15e04)
417. I'm Goin' to Praiseland (s12e19)
416. Any Given Sundance (s19e18)
415. They Saved Lisa's Brain (s10e22)
414. Take My Wife, Sleaze (s11e08)
413. Homer vs. Dignity (s12e05)
412. Maximumm Homerdrive (s10e17)
411. Marge vs. Singles, Seniors, Childless Couples and Teens and Gays (s15e08)
410. Little Big Mom (s11e10)
3/10 - Bad:
409. Wedding for Disaster (s20e15)
408. The '90s Show (s19e11)
407. Dangerous Curves (s20e05)
406. Large Marge (s14e04)
405. The Strong Arms of Ma (s14e09)
404. The Bonfire of Manatees (s17e01)
403. Take My Life, Please (s20e10)
402. Homer Simpson, This is Your Wife (s17e15)
401. The Way We Weren't (s15e20)
400. Children of Lesser Clod (s12e20)
399. Worst Episode Ever (s12e11)
398. Dude, Where's My Rnch (s14e18)
397. No Loan Again, Naturally (s20e12)
396. On a Clear Day I Can't See My Sister (s16e11)
395. Future-Drama (s16e15)
394. Homer and Lisa Exchange Crosswords (s20e06)
393. Mobile Homer (s16e13)
392. Please Homer, Don't Hammer 'Em (s18e03)
391. Kiss Kiss, Bang Bangalore (s17e17)
390. Thank God It's Doomsday (s16e19)
389. There's Something About Marrying (s16e10)
388. E-I-E-I-(Annoyed Grunt) (s11e05)
387. Midnight Rx (s16e04)
386. The Last of the Red Hot Mamas (s17e07)
385. Bart Has Two Mommies (s17e14)
384. Funeral for a Fiend (s19e08)
383. The Good, the Sad and the Drugly (s20e17)
4/10 - Dislike:
382. The Old Man and the C Student (s10e20)
381. Missionary: Impossible (s11e15)
380. When You Dish Upon a Star (s10e05)
379. Eight Misbehavin' (s11e07)
378. The Seemingly Never-Ending Story (s17e13)
377. Alone Again, Natura-Diddily (s11e14)
376. Secrets of a Successful Marriage (s05e22)
375. Goo-Goo Gai Pan (s16e12)
374. Marge Simpson in: Screaming Yellow Honkers (s10e15)
373. Lisa the Simpson (s09e17)
5/10 - Mixed:
372. Treehouse of Horror XV
371. The Computer Wore Menace Shoes (s12e06)
370. Special Edna (s14e07)
369. G.I. (Annoyed Grunt) (s18e05)
368. Papa Don't Leech (s19e16)
367. I, (Annoyed Grunt)-Bot (s15e09)
366. Brake My Wife, Please (s14e20)
365. The Monkey Suit (s17e21)
364. Barting Over (s14e11)
363. Smart & Smarter (s15e13)
362. Diatribe of a Mad Housewife (s15e10)
361. Mona Leaves-a (s19e19)
360. Girls Just Want to Have Sums (s17e19)
359. Father Knows Worst (s20e18)
6/10 - Meh:
358. Four Great Women and a Manicure (s20e20)
357. Waverly Hills, 9021-D'oh (s20e19)
356. Lisa the Drama Queen (s20e09)
355. The Burns and the Bees (s20e08)
354. All About Lisa (s19e20)
353. Love, Springfieldian Style (s19e12)
352. Treehouse of Horror XVIII (s19e05)
351. Revenge is a Dish Best Served Three Times (s18e11)
350. Kill Gil, Vol. 1 & 2 (s18e09)
349. Moe'N'a Lisa (s18e06)
348. Treehouse of Horror XVII (s18e04)
347. Homer and Marge Turn a Couple Play (s17e22)
346. The Wettest Stories Ever Told (s17e18)
345. Million Dollar Abie (s17e16)
344. We're on the Road to D'ohwhere (s17e11)
343. Homer's Paternity Coot (s17e10)
342. Simpsons Christmas Stories (s17e09)
341. Marge's Son Poisoning (s17e05)
340. Treehouse of Horror XVI (s17e04)
339. Home Away from Homer (s16e20)
338. The Seven-Beer Snitch (s16e14)
337. Pranksta Rap (s16e09)
336. Homer and Ned's Hail Mary Pass (s16e08)
335. Mommie Bearest (s16e07)
334. Margical History Tour (s15e11)
333. Treehouse of Horror XIV (s15e01)
332. The Bart of War (s14e21)
331. Mr. Spritz Goes to Washington (S14e14)
330. A Star is Born Again (s14e13)
329. Pray Anything (s14e10)
328. How I Spent My Strummer Vacation (s14e02)
327. Gump Roast (s13e17)
326. Blame It on Lisa (s13e15)
325. Tales from the Public Domain (s13e14)
324. The Old Man and the Key (s13e13)
323. The Lastest Gun in the West (s13e12)
322. Sweets and Sour Marge (s13e08)
321. A Hunka-Hunka Burns in Love (s13e04)
320. Homer the Moe (s13e03)
319. The Parent Rap (s13e02)
318. Simpson Tall Tales (s12e21)
317. Simpson Safari (s12e17)
316. The Great Money Caper (s12e07)
315. A Tale of Two Springfields (s12e02)
314. Bart of the Future (s11e17)
313. Faith Off (s11e11)
312. Beyond Blunderdome (s11e01)
311. Simpson Bible Stories (s10e18)
310. Homer to the Max (s10e13)
309. Sunday, Cruddy Sunday (s10e12)
308. Viva Ned Flanders (s10e10)
307. Treehouse of Horror IX (s10e04)
306. Lost Our Lisa (s09e24)
305. Simpson Tide (s09e19)
304. Dumbbell Indemnity (s09e16)
303. The Last Temptation of Krust (s09e15)
302. Bart Carny (s09e12)
301. All Singing, All Dancing (s09e11)
300. Realty Bites (s09e09)
299. The Two Mrs. Nahasapeemapetilon (s09e07)
298. Treehouse of Horror VIII (s09e04)
297. A Fish Called Selma (s07e19)
296. The Day the Violence Died (s07e18)
295. The Simpsons 138th Episode Spectacular (s07e10)
294. Another Simpsons Clip Show (s06e03)
293. Krusty Gets Kancelled (s04e22)
292. So It's Come to This: A Simpsons Clip Show (s04e18)
291. Treehouse of Horror II (s03e07)
290. The War of The Simpsons (s02e20)
289. Old Money (s02e17)
288. Some Enchanted Evening (s01e13)
287. The Crepes of Wrath (s01e11)
286. Homer's Night Out (s01e10)
285. The Call of The Simpsons (s01e07)
7/10 - Okay:
284. Kill the Alligator and Run (s11e19)
283. Treehouse of Horror XIX (s20e04)
282. Treehouse of Horror XI (s12e01)
281. Treehouse of Horror XII (s13e01)
280. Tennis the Menace (s12e12)
279. Treehouse of Horror XIII (s14e01)
278. Treehouse of Horror VII (s08e01)
277. Saddlescore Galactica (S11e13)
276. Stop or My Dog Will Shoot (s18e20)
275. The Front (s04e19)
274. Simpsons Spin-Off Showcase (s08e24)
273. Homerpalooza (s07e24)
272. Weekend at Burnsies (s13e16)
271. Principal Charming (s02e14)
270. Two Bad Neighbors
269. Trouble with Trillions (s09e20)
268. Boy-Scoutz 'n the Hood (s05e08)
267. A Streetcar Named Marge (s04e02)
266. Marge Gets a Job (s04e07)
365. Burns' Heir (s05e18)
364. Day of the Jackanapes (s12e13)
8/10 - Like:
263. Treehouse of Horror X (s11e04)
262. D'-oh-In' in the Wind (s10e06)
261. Apocalypse Cow (s19e17)
260. The Otto Show (s03e22)
259. Brother, Can You Spare Two Dimes (s03e24)
258. Old Yeller-Belly (s14e19)
257. Today, I Am a Clown (s15e06)
256. The Wife Aquatic (s18e10)
255. Three Gays of the Condo ((s14e17)
254. E. Pluribus Wiggum (s19e10)
253. The Italian Bob (s17e08)
252. The Canine Mutiny (s08e20)
251. Hello Gutter, Hello Fadder (s11e06)
250. Lady Bouvier's Lover (s05e21)
249. Homerazzi (s18e16)
248. Simple Simpson (s15e19)
247. The Great Louse Detective (s14e06)
246. Springfield Up (s18e13)
345. You Kent Always Say What You Want
244. In the Name of the Grandfather (s20e14)
243. She of Little Faith (s13e06)
242. Fear of Flying (s06e11)
241. Selma's Choice (s04e13)
240. Trash of the Titans (s09e22)
239. The Ziff Who Came to Dinner (s15e14)
238. Eeny Teeny Maya Moe (s20e16)
237. All's Fair in Oven War (s16e02)
236. Bart vs. Lisa vs. 3rd Grade (s14e03)
235. Lost Verizon (s20e02)
234. Jazzy and the PussyCats (s18e02)
233. Crook and Ladder (s18e19)
232. Mom and Pop Art (s10e19)
231. The Cartridge Family (s09e05)
230. Fat Man and Little Boy (s16e05)
229. Milhouse Doesn't Live Here Anymore (s15e12)
228. Yokel Chords (s18e14)
227. C.E.D'oh (s14e15)
226. The Dad Who Know Too Little (s14e08)
225. Smoke on the Daughter (s19e15)
224. Sex, Pies and Idiot Scrapes (s20e01)
223. 'Scuse Me While I Miss the Sky (s14e16)
222. The Fat and the Furriest (s15e05)
221. Dial 'N' for Nerder (s19e14)
220. See Homer Run (s17e06)
219. Life on the Fast Lane (s01e09)
218. Treehouse of Horror (s02e03)
217. There's No Disgrace Like Home (s01e04)
216. The Old Man and the Lisa (s08e21)
215. Make Room for Lisa (s10e16)
214. Guess Who's Coming to Criticize Dinner (s11e03)
213. Dog of Death (s03e19)
212. The Way We Was (s02e12)
211. Oh Brother, Where Art Thou (s02e14)
210. He Loves to Fly and He D'ohs (s19e01)
209. Bart Gets Hit by a Car (s02e10)
208. Bart's Dog Gets an F (s02e16)
207. Lisa the Skeptic (s09e08)
206. Thirty Minutes Over Tokyo (s10e23)
205. Pokey Mom (s12e10)
204. Little Girl in the Big Ten (s13e20)
203. The Bart Wants What it Wants (s13e11)
202. Homer Defined (s03e05)
201. Duffless (s04e16)
9/10 - Love:
200. My Fair Laddy (s17e12)
199. Team Homer (s07e12)
198. Don't Fear the Roofer (s16e16)
197. Ice Cream of Margie (with the Light Blue Hair) (s18e07)
196. 'Tis is the Fifteenth Season (s15e07)
195. New Kids on the Blecch (s12e14)
194. Marge in Chains (s04e21)
193. Radioactive Man (s07e02)
192. I Don't Wanna Know Why the Caged Bird Sings (s19e04)
191. Little Orphan Millie (s19e09)
190. Jaws Wired Shut (s13e09)
189. The Blunder Years (s13e05)
188. Midnight Towboy (s19e03)
187. Papa's Got a Brand New Badge (s13e22)
186. The Joy of Sect (s09e13)
185. Monty Can't Buy Me Love (s10e21)
184. Girly Edition (s09e21)
183. The Secret War of Lisa Simpson (s08e25)
182. Mr. Lisa Goes to Washington (s03e02)
181. A Star is Burns (s06e18)
180. Bart the Fink (s07e15)
179. The Wandering Juvie (s15e16)
178. The Girl Who Slept Too Little (s17e02)
177. I'm Spelling as Fast as I Can (s14e12)
176. She Used to Be My Girl (s16e04)
175. The Principal and the Pauper (s09e02)
174. Bye, Bye, Nerdie (s12e16)
173. The Heartbroke Kid (s16e17)
172. Home Sweet Homediddly-Dum-Doodily (s07e03)
171. Homer Alone (s03e15)
170. Mayored to the Mob (s10e09)
169. Lisa the Tree Hugger (s12e04)
168. Lisa the Iconoclast (s07e16)
167. Homer Goes to College (s05e03)
166. Bart's Inner Child (s05e07)
165. I'm with the Cupid (s10e14)
164. Days of Wine and D'oh'ses (s11e18)
163. Lisa vs. Malibu Stacy (s05e14)
162. Gone Maggie Gone (s20e13)
161. I Am Furious Yellow (s13e18)
160. Bart Gets Famous (s05e12)
159. Homer's Odyssey (s01e03)
158. Bart the Genius (s01e02)
157. Homer and Apu (s05e13)
156. Insane Clown Poppy (s12e03)
155. Bart the Mother (s10e03)
154. Homer the Heretic (s04e03)
10/10 - Best:
153. A Star is Torn (s16e81)
152. The Haw-Hawed Couple (s18e08)
151. Fraudcast News (s15e22)
150. King-Size Homer (s07e07)
149. Brother from the Same Planet (s04e14)
148. This Little Wiggy (s09e18)
147. The Twisted World of Marge Simpson (s08e11)
146. Brother's Little Helper (s11e02)
145. Simpsoncalifragilisticexpiala(Annoyed Grunt)icious (s08e13)
144. Sleeping with the Enemy (s16e03)
143. The Mook, the Chef, the Wife and Her Homer (s18e01)
142. Deep Space Homer (s05e15)
141. Homer the Smithers (s07e17)
140. Grift of the Magi (s11e09)
139. Hungry, Hungry Homer (s12e15)
138. The Homer They Fall (s08e03)
137. Scenes from the Class Struggle in Springfield (s07e14)
136. The Springfield Connection (s06e23)
135. Bart Gets an Elephant (s05e17)
134. Homer Badman (s06e09)
133. Mountain of Madness (s08e12)
132. Burns, Baby Burns (s08e04)
131. My Mother the Carjacker (s15e02)
130. MyPods and Boomsticks (s20e07)
129. How the Test Was Won (s20e11)
128. The Wizard of Evergreen Terrace (s10e02)
127. King of the Hill (s09e23)
126. The Mansion Family (s11e12)
125. Natural Born Kissers (s09e25)
124. Homer the Vigilante (s05e11)
123. Saturdays of Thunder (s03e09)
122. Simpson and Delilah (s02e02)
121. Three Men and a Comic Book (s02e21)
120. Brush with Greatness (s02e18)
119. Much Apu About Nothing (s07e23)
118 Simpsons Roasting on an Open Fire (s01e01)
117. Two Cars in Every Garage and Three Eyes on Every Fish (s02e04)
116. Itchy & Scratchy: The Movie ((s04e06)
115. Dancin' Homer (s02e05)
114. Bart After Dark (s08e05)
113. The Springfield Files (s08e10)
112. Bart on the Road (s07e20)
111. HOMR (s12e09)
110. Lisa the Beauty Queen (s04e04)
109. Lisa the Greek (s03e14)
108. Burns Verkaufen der Kraftwerk (s03e11)
107. Whacking Day (s04e20)
106. The City of New York vs. Homer Simpson (s09e01)
105. Behind the Laughter (s08e16)
104. Brother from Another Series (s08e16)
103. Homer's Phobia (s08e15)
102. The Itchy & Scratchy & Poochie Show (s08e14)
101. Two Dozen and One Greyhounds (s06e20)
100. Who Shot Mr. Burns - Part Two (s07e01)
99. Itchy & Scratchy Land (s06e04)
98. Treehouse of Horror IV (s05e05)
97. Treehouse of Horror III (s04e05)
96. Treehouse of Horror VI (s07e06)
95. Treehouse of Horror V (s06e06)
94. I Love Lisa (s04e15)
93 The Telltale Head (s01e08)
92. Homer Loves Flanders (s05e16)
91. The Boy Who Knew Too Much (s05e20)
90 One Fish, Two Fish, Blowfish, Blue Fish (s02e11)
89. Homer vs Lisa and the 8th Commandment (s02e13)
88. Krusty Gets Busted (s01e12)
87. Black Widower (s03e21)
86. I Married Marge (s03e12)
85. Rosebud (s05e04)
84. Stark Raving Dad (s03e01)
83. Like Father, Like Clown (s03e06)
82. Springfield (s05e10)
81. Bart Star (s09e06)
80. The DeBarted (s19e13)
79. The President Wore Pearls (s15e03)
78. Last Tap Dance in Springfield (s11e20)
77. My Sister, My Sitter (s08e17)
76. Radio Bart (s03e13)
75. Sideshow Bob's Last Gleaming (s07e09)
74. Homer vs. Patty and Selma (s06e17)
73. Eternal Moonshine of the Simpson Mind (s19e09)
72. Moe Baby Blues
71. You Only Move Twice (s08e02)
70. Sweet Seymour Skinner's Badass Song (s05e19)
69. Bart's Comet (s06e14)
68. The Last Temptation of Homer Simpson (s05e09)
67. In Marge We Trust (s08e22)
66. Homer's Enemy (s08e23)
65. Kamp Krusty (s04e01)
64. Mr. Plow (s04e09)
63. The Last Exit to Springfield (s04e17)
62. Homer's Barbershop Quartet (s05e01)
61. Marge Gamer (s18e17)
60. Das Bus (s09e14)
59. Lisa's Date with Density (s08e07)
58 Itchy & Scratchy & Marge (s02e09)
57. Dead Putting Society (s02e06)
56. Homer the Great (s06e12)
55. Bart vs. Australia (s06e16)
54. The Curse of the Flying Hellfish
53. 24 Minutes (s18e21)
52. When Flanders Failed (s03e03)
51. Lisa's Wedding (s06e19)
50. Blood Feud (s02e22)
49. El Viaje Misterioso de Nuestro Jomer (s08e09)
48. Hurricane Neddy (s08e08)
47. A Milhouse Divided (s08e06)
46. Bart of Darkness (s06e01)
45. Bart the Daredevil (s02e08)
44. Moaning Lisa (s01e06)
43. Round Springfield (s06e22)
42. Bart the Lover (s03e16)
41. Colonel Homer (s03e20)
40. Homer at the Bat (s03e17)
39. Skinner's Sense of Snow (s12e08)
38. Lisa's Pony (s03e08)
37. Lisa on Ice (s06e08)
36. Wild Barts Can't Be Broken (s10e11)
35. Bart vs. Thanksgiving (s02e07)
34. Bart the General (s01e05)
33. Marge vs. the Monorail (s04e12)
32. Homer vs. the Eighteenth Amendment (s08e18)
31. Lisa Gets an A (s10e07)
30. 22 Short Films About Springfield
29. And Maggie Makes Three (s06e13)
28. Who Shot Mr. Burns - Part One (s06e25)
27. Marge on the Lam (s05e06)
26. Sideshow Bob Roberts (s06e05)
25. Marge Be Not Proud (s07e11)
24. New Kid on the Block (s04e08)
23. Grade School Confidential (s08e19)
22. Bart's Friend Falls in Love (s03e23)
21. Lard of the Dance (s10e01)
20. Lisa's Sax (s09e03)
19. Separate Vocations (s03e18)
18. Bart the Murderer (s03e04)
17. Lisa the Vegetarian (s07e05)
16. Trilogy of Error (s12e18)
15. The PTA Disbands (s06e21)
14. Cape Feare (s05e02)
13. Bart Gets an F (s02e01)
12. Lisa's First Word (s04e10)
11. Homer's Triple Bypass (s04e11)
10. Lemon of Troy (s06e24)
9. Flaming Moe's (s03e10)
8. Grampa vs Sexual Inadequacy (s06e10)
9. Bart's Girlfriend (s06e07)
8. Homie the Clown (s06e15)
5. Mother Simpson (s07e08)
4. Summer of 4 Ft. 2 (s07e25)
3. Lisa's Substitute (s02e19)
2. Lisa's Rival (s06e02)
1. Bart Sells His Soul (s07e04)