I'm going to try to post all of the ideas I've had since 1997 in this topic. This will take several replies due to a posting size limit.
1. "The Yellow Years"
Ancident at the plant causes Homer to grow younger day by day.
2. "My Favorite Martin"
Martin is actually an alien out to kidnap all the brainy children and use them on his homeworld's plan to overthrow Rigel 7.
3. "The Six Million Dollar Boy"
Bart's involvement in a Skateboarder accident leads to an operation that makes him bionic. Now the strongest, fastest, kid in school, Bart's the force to be reconned with, until his machine half goes haywire.
4. "The Watermelon Woman"
After Bart eats some bad Chinese food and goes to bed, he wakes up a young lady.
5. "Reaction Figures"
Lisa's collection of Malibu Stacys come alive and try to do her in.
6. "Dueling Yahoos"
Homer's solo cross-country drive Home winds a up matter of survival as a manical trucker tries to take him down.
7. "Our Way, Right Away"
Homer, Lenny, Carl, and Smithers are layed off and end up working at Krusty Burger.
8. "Legally Blind Date"
A computer match at school hooks Lisa up with Millhouse as part of a dating-excercise, but she is almost willing to get an "F" to avoid him.
9. "...and they Got to Writing"
Homer and Marge try to write a book about marital bliss, but wind up causing more divorces after the book is published.
10. "Ten Little Springfieldians"
In an Agetha Christy-esque tale, Homer and Marge spend a weekend with other couples at an island-based bed and breakfast, but have a hard time finding pleasure as the residence are killed off, on at a time.
11. "A Star is Torn"
Lisa's hope for stardom is cut short when the company she recorded some sax solo's steals her music. Furious, Lisa tries to take down the comapany.
More THoH ideas:
12. "Arrgh-Agnesphobia" Halloween Short:
Agnes is cloned and Springfield's most annoying citizen litteraly becomes 'everybody's mother.'
13. "Dr. Jeckyl and Mr. Simpson" Halloween Short:
Homer is given an experimental syrum that gives him good looks and a pleasent personalitly, but wears off and he becomes his old grumpy self every few hours.
14. "Attack of the 50 Foot Maggie" Halloween Short:
Maggie is 'accidently' given the growth medication and within a few hours, is trouncing around Springfield.
15. "The Thin, R.E.M. Line"
Marge's increasing sleepless nights force her to go to a sleep center for treatment. Meanwhile, Homer and the kids take up the adopt a highway program to pick up trash along route 401. While frolicing in the ditch, Bart trips over part of a buried World War II Jeep. After digging out the jeep, Homer and the kids find a soldiers skeleton and a security box that contains a map to some undelivered, buried gold someplace near Springfield.
16. "Below Hero"
When a minor earthquake rocks Springfield, Homer helps the Flanders to safety, but falls down an open fissure into the blackness. Mistaken for dead, Homer tries to make his way back to the surface and discovers a few neat things below Springfield.
17. "Somthing...Mell's Funny":
Sideshow Mell takes over for Krusty after his boss is seriously injured in a live stunt. Taking some pointer from Krusty's number one fan, Bart, Mell becomes a star. The only snafu is that Mell's popularity soars and nobody really wants Krusty to comeback.