Hmm, tough one, so many to choose from, at least from the 60s to the 90s.
1 Doctor Who (classic)
2 The Avengers
3 Callan
4 Taggart (the version that actually has Taggart in it from 83-95)
4 Blackadder
5 The Young Ones
6 Drop the Dead Donkey
7 Father Ted
8 Miss Marple (Hickson)
9 Sherlock Holmes (Brett)
10 One Foot in the Grave
Bubbling under: Robin of Sherwood, The Bill (1984-2001), Jonathan Creek (pre-season 5 anyway), Only Fools and Horses, The PD James Mysteries (with Roy Marsden), Red Dwarf
British TV was the best up until the 90s, where the US did briefly supercede it. They both suck now though.
