I've got GoldenEye 007 for this generation as far as "traditional/multiplayer" FPS' go, and that's enough for me. Sure I'll play some Halo once and a while when friends are over, but other than that... really only 1-2 FPS games are all I need a generation.
Now... this doesn't include Bioshock and the upcoming "prequel" Infinite, which I cannot wait for. With their focus on Single Player and untraditional FPS elements... I'm all for it.