I haven't played Darkest of Days, but a preview I read made it sound like Timesplitters with Ben-Hurish scope. Just looking at an actual screenshot makes me nearly cringe, though.
Wet could have been alot more fun. I mean, I even enjoyed the demo.
Mirror's Edge could have been excellant if they had less freaking guns that you almost need to use.
I desperately tried to love GTA 4, but it was so shallow in terms of actual shit to do that I couldn't.
And Red Faction Guerrilla. Have an option to respawn structures, that would have alleviated so many complaints I have about the game.