I saw "Saddlesore Galactica" in syndication the other day, and it's still one of the more frustrating episodes of season 12. And not because the episode is all bad, but because it had such a great Act 1, a mediocre Act 2 (when the horse is introduced) and a horrid Act 3 (with the jockey elves.)
I still love the first 8-10 minutes of this show. The whole sequence with Lisa's band practice ("soemthing _arranged_ by Sousa?", the Sinatra-like kid saying "Hey, this cat's got claws!"), the bits at the county fair: Homer with the ticket taker ("They didn't ask for ID when I fought Charlie at La Choy and Chun King!"), Homer yelling at BTO, ("No talking, no new crap, Taking Care of Business, NOW!!"), the Omnigogs booth, Lisa being mad at losing, etc. I still laugh at it all. But I usually turn it off after CBG's meta-reference, which foretold exactly how derivitive and silly the rest of the show was about to be.
Anyone else have a "favorite" episode that starts out good but goes wrong?