i completed halo 5 on legendary. halo combat evolved i think i finished on normal. halo reach i only got halfway through, i didn't start halo 2 or three, and i got through 3 missions of halo 4. halo wars 2 i have completed on the hardest difficulty, and while i did play 1 mission of halo wars one, the graphics sucked so i stopped playing.
@Turtle
i also got the add-ons to halo wars 2 and completed those as well.