Great story, Great gameplay, Great game
Fallout 3 has one of the best storylines of all time. It lets you pick what you want to do, how you want to do it. Its soundtrack is amazing! Its fighting is amazing with the wide range of wepons starting at a simple hand gun to a lazer rifle all the way to a mini gun! With V.A.T.S even when you are surrounded you can still have a chance at winning.
Fallout 3 is the best RPG this generation. The story is well done, the gameplay is solid, it'll have you coming back for more, and there is just so much you can do.
I ended up beating it twice, and I had to force myself to delete the save because I'd end up getting totally sucked into it again.