While I agree that Luca$ is a terrible episode, I don't see how Homer asking Lisa out is anywhere close to the depths of scenes like Moe kissing Katy Perry's "bellybutton," Bart leaving his father to be hanged, a one-minute list gag in White Christmas Blues, and so on. I think it could have been a good episode if they had gone with the angle of giving Lucas and Lisa a real relationship and portraying Lucas as a Homer-type, which leads Marge to try to convince Lisa against the relationship (with no repetitive marriage crisis plot in sight, although a couple of scenes wouldn't hurt). The Snake subplot could have worked too, but it was paper-thin and nothing really happened.

Regarding ofhf's suggestion, Coming to Homerica is above-average but not outstanding. The jokes are fairly mediocre but the plot is strong (essentially a better version of White Christmas Blues).