Halo 2 is gonna just plain rock. After seeing both trailers for Doom 3 and Halo 2, I have come to the conclusion that Halo 2 will probably be better. The difference in graphics isn't much, both having breathtaking visuals, but you have to remember one thing... Doom 3 is succesfully creating a scary atmosphere with totally black shadows and dramatic lighting effects, whereas Halo 2 is just... different. It will have beutiful outdoors (that I cannot see Doom 3 having), lots of space seeming atmosphere but no doubt some scary atmosphere too (like on "The Truth and Reconsiliation" on the original halo and many other tense and jumpy moments whilst battling through the metallic complexes).
I have to say that Doom 3 had something that i appreciated very musch that Doom 3 didn't appear to have... (could be wrong) and that is lense focusing. Well, I don't know what its actually called, but its when the camera focuses on something in the background and the foreground is blurred (and vise versa) like in real life. It is just so cool.
I'm also willing to bet that Halo 2's story will be far superior to Doom 3's.
Another point to be made, for those of you that didn't like the metallic levels in the original Halo (and thought it was repetitive, I for one liked them and see a variation of indoor levels as a bonus), then you can bet that the locations of indoor levels in Halo 2 will be alot more different than each other, seeing that its on Earth and how much eveybody likes to be different
I'm not sure if its all on earth, I'm betting that visiting other Halos will come into the game.
And there are much more vehicles in the game. I read the other day at a website that I lost the address to (got it at gamespy) that there are different types of warthogs in the game... snowhogs being one (for snow of course), a camoflaged one for forest areas being another and I forget about the other ones. there is also a people carrier to transport alot of troops around (and each other on online cooperative (being much more than 2 player)) in and many other vehicles. There is alot more that has been put into the game, and I really cannot wait
But I want to wait, because then I know that the game will be perfect without bugs if I do