Jeeves and Wooster is very good. I would recommend that you space out the seasons, though, because if you watch them all quickly, there is a bit of "They're going to New York AGAIN?" that gets in the way of your enjoyment. Better to come back to it fresh.
All the Blackadders are good. I really like the British mystery/crime miniseries: Messiah, Prime Suspect (of course), Murphy's Law, Jonathan Creek, Waking the Dead (so much better than any American crime series, and I like the American ones, too), even Murder in Suburbia. Although maybe that last one is that I would be willing to watch Caroline Catz or Lisa Faulkner for an hour just because.
You can tell British people are smart because of the way they talk.