Spaaaaced! (2 seasons)
You're a brit, man, it's mandatory, though it's debatable wether it's finished or not.
I'm in the middle of Jeeves and wooster now, Hugh laurie and stephen fry! (3 seasons)
I see Black Books have been mentioned, so I'll second that, you will find nothing like Bernard/Dylan Moran anywhere else. (3 seasons)
Seen Carnivàle? Twin Peaks? Green Wing? (All three 2 seasons each)
Personally I'm a big sucker for yes minister/prime minister. (5 seasons)
I suppose you're young enough to have missed Black Adder on the telly, unless it has been re-screened to death.
Carl Sagans Cosmos, if you're into the bigger questions (one season)
The genius of photography (one season)