I've finished all the campaigns again, besides Reach, out of order. I started with 2 cause that's what I really wanted to play, and it just snowballed from there.
I even reinstalled Halo War 2 and bought Halo Wars Definitive on Steam cause it was only a few dollars. Replayed both of those as well.
Then I got Spartan Assault and Spartan Strike, which are bundled for like $3 cause they're mobile games first, but they're basically twin-stick shooters with extra added story.
I just like the Halo games, man. They speak to me in the language every young kid knows/knew: The Rule of Cool.