Burns and Allen was, in my opinion, one of the finest shows ever.
I enjoyed Green Acres as a kid, and surprisingly, found it still entertaining, mostly because it was just plain dopey and the writers knew it. There's a kind of surreal feeling about the whole show.
Alfred Hitchcock Presents was a quality show.
A few modern shows that I got hooked on: Alias, Boston Legal, Sopranos, Desperate Housewives.

Thanks to the British, we've been treated to a few gems: To the Manor Born, Keeping up Appearances, Good Neighbors, Mapp and Lucia, Jeeves and Wooster, a few dozen detective series.

And when I just want to watch pleasant people being pleasant, the Brits gave us Monarch of the Glen and Ballykissangel. Mulberry is also sort of fun, but only available through Netflix here in the States. Same with The Darling Buds of May, At Home with the Braithwaites and Doc Martin (first season only).

And the BBC news is the best available, although the other day they spent the first ten minutes talking about that Jackson guy. I'll forgive them just this once. Nobody's perfect.