I adored it. In terms of feature set, I saw it as Bungie's greatest Halo hits plus--all in one package. I spent more time exploring that game world than any other, in no small part due to the amazing (to this day) Theater mode, which let you relive anything from any angle. Of course it spawned Co-op Night, which bumped up my participation in the community, which led to many friendships that I cherish to this day. I made a comic
out of it (while teaching myself photoshop ), I went to my first of many out-of-state LANs, attended the amazing Halofest, met some of my heros at Bungie, and got to know some of my heros in this great community. For so many firsts, Halo Reach was in the background--the watering hole where we all returned on a near-nightly basis. I won't forget Reach.
Here's a little found footage I dug up showing what you could discover in Theater mode.
Kat gets bored.
For full effect, though, you need to read Mig's original commentary.
Thanks again, Bungie! I thought your Halo sign-off was damn-near perfect.