Coupling wants to be Friends - it's an unashamed copy. Has it's moments, like Friends, but I don't really like either.
My list:
1) Fawlty Towers - superbly written and casted - only 12 episodes but every one a gem especially the Waldorf Salad episode:
"I think we're out of Waldorfs..."
2) Father Ted - surreal in the extreme. Easily the best sitcom to come out of Britain since Fawlty Towers. The episodes where Father Ted has to kick Bishop Brennan up the arse are my favourites.
3) Blackadder Goes Forth