RED DWARF! (If that weren't already obvious)
I just love its perfect blend of mockery, comedy and of course science fiction. I love how it simply yet elegantly pits a slobby human, a smeghead hologram, a self-obsessed cat descendant and an anal android (Yes I know Krytten only came in a few series into it, and Kachanski (I don't really know how to spell it) was there for a while, because I consider those four to be the real cast) against the worst possible odds, and yet they always live through to see the next curry night. Coincidentally, I spent most of the weekend watching my new dvd of it, and I'm watching it tonight (They do re-runs on ABC2, that's how I got into it)
Hell! Screw it being the best British show on television, more like the best show there is on television!