In my opinion, halo 3 is the worst...eesh, Im going to get a lot of hate for that... but the best one's got to be reach, halo is a great series, with the games, books, graphic novels and movies, but if you're not an fps fan, you're probably not going to like it. I'm not big on fps' s, but halo is one of my favorite games of all time, behind zelda of course. (sorry harvest moon and animal crossing... but halo's better...)