Willow, as for Seinfeld, you say that you don't find Jerry funny but mabe people are laughing at Kramer... you've actually missed the funniest character in the show, George. Jerry is sort of the straight man, and Kramer the slapstick element, but I think George as a character is the funniest. Seinfeld and Larry David actually based the show on themselves, with george being based on David.
I like Seinfeld but like others no episodes stand out that much. Some of my comedy favourites:
Bottom
Fawlty Towers
The Simpsons
Red Dwarf (early with episodes with Rimmer only, Kochanski was NOT funny)
Monty Python
Ali G
South Park
King of the Hill
Beavis and Butthead
I've included the cartoon ones because while they are cartoons they follow the typical comedy show hqalf hour episode format, The Simpsons and especially King of the Hill are really just comedy shows with drawn instead of real characters. I also like a lot of more fully cartoon type shows like Ren and Stimpy (early Spumco episodes) Cow and Chicken, Pinky and the Brain etc.