Oh no, I agree. 1 is 100% a good game just because of the story. The MP was awesome because besides Goldeneye/Perfect Dark there wasn't anything like it at the time, but it's balance was definitely lacking.
I still remember not even knowing what Halo was when we got an Xbox for Christmas. My brothers and I booted that thing up and it was probably the most in-awe experience of my gaming life since original EQ. I remember looking up and seeing the ring wrap around and understanding I was on the inside of a giant fucking structure and could see across the world, so to speak, by just looking up. Mindblowing. The story was fine, the music was amazing, but the Campaign was really, really well done. I've gone back and played it when the MCC launched on XB1. Just dealing with fucking Hunters at certain times and shotgunning flood except for poppers. Great stuff.
Halo 2 actually had a legit campaign with the Arbiter (Keith fucking DAVID) and their soundtrack done by Incubus (lul). The last level of Halo 2 was probably the most fun driving around while everything just explodes around/under you. The song "Follow" they wrote was pretty good for a video game song too.
Obviously nothing beats the original Halo song. Amazing.