I have to add The Fast Show (and the most sublime character in it, Rowley Birkin QC).

And astonishingly, no-one has mentioned Father Ted.

If one is a true aficionado of British humour, you really need to get hold of the radio recordings from "I'm Sorry I Haven't a Clue". Utterly brilliant improvisation and the highest pinnacle of the double entendre and venomous pun. Some snippets here. If you haven't heard this Louis, make every effort - you will adore every second.