I regularly watch The Discovery Channel, The History Channel, and The Learning Channel when I'm browsing around.
But there are three shows that I'll set the VCR to see.
Buffy The Vampire Slayer, Angel, and Farscape. All three shows are funny because they know how campy they are and play to that as a strength. But they also have serious storylines where main characters actually change over the course of the show--something rare on Television in the US.
I think Farscape is the best Sci-Fi show on TV. (Sorry, Logical, but Voyager is the worst of the Trek franchise--though Enterprise looks like it will surpass it.)
I also do my best to catch Cirque de Soleil on Bravo. Those people are frelling amazing!
Hmmm