BL2 has my vote. AC3 is just more of the same, and I've never understood the huge hype behind Halo. I know they're like "The Beatles" of first person shooters, but The Beatles didn't look as amazing once other rock bands formed.
The Beatles and Halo are both purposefully crafted to be mainstream.
That said BL2 is not going to win because "Oh man ARM BLADES" and I mean obviously Halo is liek da best sh00t3r eva
AC3 is actually a really good game, I understand halo but credit is due where credit is due. It's night and day from the other ones, it's not the same thing. Jus saying. Good game. I love this though, and halo is like cod.
I'm more of a salmon kinda guy myself. --- XBL gamertag: Z3r074 (the 0 is the number zero)