The thing about British TV is that they know when to stop making a show. They don't drag it on to milk more money out of it. The Office, Green Wing, Little Britain, immediately come to mind as more recent shows. BlackAdder. They don't have 7+ seasons like the American Office does. It didn't ruin a fine ending of season three with a shitty season 4 like Arrested Development did. Family Guy is still going. South Park is up there, but it's somewhat relevant since it mocks more recent events. But look how long it took a shit show like The Cleveland Show to get cancelled. Big Bang would have been great had it ended after season 4 or 5. But they have to keep stretching it on.
It sucks such good British shows are only a few episodes a season and only like, 3 seasons, but maybe that's what makes them great. They get all the ideas out there at once, and then let it be.
Anyone take my suggestion of watching the The Increasingly Poor Decisions of Todd Margaret? Great show. Not sure if it qualifies as a British show, since I don't know who made it.