Alton Brown's "Good Eats is probably the best show on the Food Network. It's a little corny the way it tries to be "Wacky" but the format of the show is very educational. He picks a single ingredient or dish, then spends half an hour going ino the preparation in depth. He also does a great job explaining the chemistry behind cooking in a way a general audience can understand.
If you've taken college-level chemistry, obviously it's a little simplified, but you can still see the principles he's talking about. The chemistry side of cooking is interesting, and it's something other shows never go into at all.