Any Transformers. old, new, old japan, new japan.
GI Joe (not that GI Joe EXtreme crap though)
Silverhawks
Voltron
Widget the World Watcher
James Bond, Jr.
Teenage Mutant Ninja Turtles.
Robotech

New cartoons can be cool, but mostly if they're Transformers or Anime.

Trigun
Outlaw Star
DBZ
Evangelion

come on... they're good.