Jeopardy
Gilligan's Island
Johnny Quest (the original series - the New Adventures theme was okay, but the original was much better)
Batman Beyond
Aqua Teen Hunger Force
Harvey Birdman, Attorney At Law
The Jetsons
The Simpsons
Mission Impossible
Knight Rider
The A-Team (original theme; NOT the version from after it jumped the shark (ie, when they added Robert Vaughn to the show)
Happy Days
Magnum P.I.
X-Men (the old Jim Lee art based cartoon, NOT X-Men Evolution)
Thundercats (`Thundercats are on the move. Thundercats are loose!')
G.I. Joe (`They'll fight for freedom, wherever there's trouble. G.I. Joe is there!')
Transformers (original, Armada or Energon)
Airwolf
Doctor Who - particularly the Jon Pertwee and Tom Baker versions of theme - including the later Tom Baker version that was also used by Peter Davison (and I think Colin Baker)
Star Trek - Original series and Next Generation
Not sure if Iron Chef counts, since the opening theme is actually the end theme to the movie Backdraft....
If you want to include anime, then....
Gigantor
Inuyasha (particularly the Deep Forest and Dearest themes)
Cowboy Bebop (Tank! and Real Folk Blues)
Lupin the Third
Martian Successor Nadesico
Tenchi Muyo (the theme from the OVAs)
And Ixistant? The Teen Titans theme IS Japanese Rock!