I'm not much a multiplayer FPS guy or a 1st-person-shooter guy in general but I do enjoy a good FPS campaign from time to time. I'm bout to start a playthrough of a well-regarded FPS campaign I missed from last gen, Battlefield: Bad Company, which made me want to ask y'all this question. I did enjoy Doom last year but looking back, it definitely could've been trimmed here and there. Overall though, as someone who's not that versed in the genre, it's up there for sure for me.
Anyway, what's your favorite FPS campaign and what do you like so much about it?