Halo 1 by far, it's one of the best games ever. I must have played through it at least 5 times now!
Halo 2 was disappointing, it just wasn't as open-ended as the first one. And the ending pissed EVERYONE off.
The campaign in Halo 3 was also disappointing, it was far too short. And it wasn't even set on a Halo! (Apart from the last level) Considering the Halo series had jumped a generation and there was all the "finish the fight" hype, Halo 3 simply wasn't good enough. The multiplayer is great fun though.








