If they make a movie, I hope the main character isn't the Master Chief, I'll like it if it's connected to him somehow but if they base it off him and his story people are gonna be like "OH MY GAWD!!! This movie SUCKS! That never happened!! In Halo 2 it clearly happened like this..." I'm sure you get my point. They can't make a perfect translation of the story from the games to a movie. That's the reason why some movies that came from books are sometimes hated on because they don't follow the original story line like "The Lighting Thief"
The solution to this is make a brand new story about an ODST squad or anything else. That'll be much better. Because also, if it's about Chief, we already know what's going to happen. If we have a brand new story of an ODST (or something else) we will be guessing what will happen next instead of going oh, this is where the Prophet of Truth dies. Also the writers will be able to add and remove things without people flipping over their tables.
Oh yea, and make it tragic like Reach and not happy. Haha.