Angel is great!
I like sci-fi mainly, but it would take too long to list everything I enjoy. Here's just some...
The Stargates, Buffy, the Star Treks, Twilight Zone (original), Lost In Space, Battlestar Galactica (new more than the old), Now and Again, Earth 2, Odyssey 5, Firefly, Carnivale, Farscape, 24, Planet of the Apes, Without a Trace, Smallville, Mystery Science Theater 3000... loads!
The one I make sure I don't miss being shown on TV for the first time atm is The Big Bang Theory.
All time favourite - most likely either The Outer Limits (90/00s version) or Star Trek Deep Space Nine. Early years of Stargate SG-1 are right up the top too. One of those three.