You probably won't get many replies here as most of the gamers on this forum are console gamers.
As I have a PowerBook G4 my gaming choices are limited, but for FPS I enjoyed Halo, Jedi Outcast, Star Wars: Battlefront.
Your MacBook Pro will play Call Of Duty in OS X and really any PC game if you use Boot Camp and Windows XP. You might want to try out Counter Strike.
I haven't been impressed with many of the newer games that I've seen anyway and with almost all development going over to consoles, for a variety of reasons, gaming on PC/Mac is in a decline. Most if not all games are now developed for console, and if there is enough demand then those games will be ported to PC. The only games that I currently own that were developed for PC (and ported to Mac) are Jedi Outcast and Jedi Academy, and it's those games that I keep returning to and playing, weather base or mods.