What would you score each Halo game in the 1 to 5 scale?

[Jansky8]

Halo CE: 5/5 (best XBOX games IMO)
Halo 3:3,75/5. I only played the SP, therefore I know I'm missing on the online, which is said to be one of the best out there. But the 3,75 reflects my SP experience.