I was tied between Reach & 4 but had to choose Reach because it has the better all-around campaign. If the question was "best story" it might've been different, but Reach's ensemble is still at an advantage there.
Anyway, if I were to make a list it would be
- Halo 4
- Halo 3
- Halo CE
- Halo 2
- Halo 5 Guardians
I haven't actually finished Wars & refuse to just watch the cutscenes online bc it feels cheap. One day, when I have nothing else to play...
Also, yeah 2 never really got me for some reason. It's not low bc I hate it, I just like the other ones more. Don't care for 5, tho it's not objectively horrible I guess.