Eh. Halo has never really been my game. That's probably because all my friends want to play multiplayer and Halo sucks at that. Unreal and Quake destory Halo when it comes to multiplayer. It's kick ass through the single player mode though. The visuals are amazing. Still... I'm more anxious to play Doom 3 than Halo 2.
DOOM 3 looks amazing and scary as ####, DOOM 3 will do what Halo messed up on. But since Halo isn't your cup of tea, I'll leave you at that.