after i completed Halo 3, it just died on me, i've played some multiplayer thought it was the same thing i had played for years, stopped, and i havent logged a single minute back in it since.

Sorlok

Yeah, same here (but I never played Halo multiplayer before Halo 3). I know why I can't get into it, though. I just don't like Unreal Tournament style multiplayer anymore, preferring more class-based multiplayer. A stranger game is Bioshock, though. It didn't hold my interest, and while playing I was clueless why that was so. I'm still unable to reach a conclusion on this.

As for older games, I'd say Diablo (1 and 2) stand out, as well as pretty much every major RTS to come out (excluding the Total War series) like the C&C games and more recently World in Conflict.