I'll do my best, but you have to realise the sheer magnitude of my nerdacious love for the Simpsons, so my Top 10 are so microscopically separated it's not funny.
10.
Homie The Clown - I love Krusty, and I love Homer. Together, they are gold. Also, Luigi throws out one of my all-time favourite lines, "Yeah, you see how you scum".

9.
Last Temptation of Homer - A very funny and fundamentally very sweet episode about Marge and Homer, really. Hilarious episodes are great, but the value of the episodes that tug at the heartstrings shouldn't be understated.
8.
Sweet Seymour Skinner's Badaaaass Song - Funniest Apu rant ever, some five-star Superintendent Chalmers, and one of Skinner's finest half-hours.
7.
Marge vs. The Monorail - The best song in the history of the Simpsons, Phil Hartman, and Conan O'Brien. There is nowhere this episode goes wrong.
6.
Homer The Great - Secret cults + Jean Luc Picard = ratings.
5.
Deep Space Homer - Marvellous.
4.
Krusty Gets Kancelled - Myriad of celebrities, hilarious acting (both voice and animation - Krusty's post-
Worker and Parasite face cracks me up every time)
3.
Cape Feare - Sideshow Bob's finest half-hour. I can watch this episode again and again and
again...
2.
Homer The Heretic - Simply brilliant.
1.
Last Exit To Springfield - From the get go, this episode is a non-stop train of hilarity. Seamless parodies, succinct satire, yet emotional to it's core, it is the epitome of all things Simpsonian.
I dunno, I could write that again and 70% of it would be different. It was so hard to choose.