Halo 4

A lot of other reviews bash the new art style of this game compared to the original 3 by Bungie but they don't talk about the story.

The original 3 Halo games tell an epic story about the mysterious Forerunners and saving humanity and the galaxy from the misguided Covenant.

After playing through all of the halo games in sequence I can say that none of them really dive into the character of Master Chief or Cortana with any depth. In Halo 3 we get to see a glimpse of the impression that Cortana has on Chief but even that is limited. If anything we get more character development from the Arbiter than any human character.

Halo 4 is the only game that actually focusses on Master Chief and Cortana. Master Chief is no longer a just a guy that says one-liners in cutscenes, he is a deeply damaged person who has ties and connections with people (or A. I.).

Halo 4 may not look like a Bungie Halo game but it's story rivals that of any single bungie halo title, except maybe Reach.