Might point out that if you're looking for characters to fall in love with, don't play an FPS- at least not if you want PLAYABLE characters you can fall in love with. Sure, some may have great SUPPORTING characters like Alyx Vance or GLaDOS, but your character is usually mute and completely bereft of any kind of personality. And to be honest, FPS plots aren't usually that crash hot anyway.
My personal pick is Odin Sphere for the PS2. I'm only half way through it, and it has one of the most complex and epic plots I've played in a long, long time. There are 5 playable characters, each one deep and well rounded, and they interact with each other in fascinating ways due to the fact that, since their stories happen mostly simultaneously yet in completely different chapters of the game, they're not always on the same side. Also the gamepay is interesting (if hardcore difficult and at times a bit frustrating or repetative), the complete voice acting (your choice of Japanese and English) is exceptional and the 2D graphics are beautiful beyond belief. One of those games overlooked on the same level as Beyond Good and Evil.
