I've lost count of the number of systems and titles. Ya, I still go back to D&D because it's easy to get new players, but there are a lot of other games out there. Mutants & Masterminds, Star Wars (D6 or D20,) Starship Troopers, Werewolf (Apocalypse or Forsaken,) Rifts, Star Trek, Deadlands, Earthdawn, 7th Seas, Cyberpunk and Toon top my list of things I've been involved with and would love to do again.
There is life outside of D&D.