In my early childhood, the go to FPS was GoldenEye 007, and it was a lot of fun. I didn't play it for the story: the multiplayer was what made it great.
A couple of years later, Halo came out on Xbox, and wow was it great. Not only was the multiplayer fantastic, but it had a great story and soundtrack as well. Over the years, the FPS genre has become over-saturated, but Halo continues to stand out because of its well-designed universe and story. I do admit, I have lost a bit of interest since Halo 4. It kind of seems like it should have ended with the trilogy (I guess with Reach and Wars included).