I beat Reach. Awesome. Definitely my second favorite in the franchise behind Halo: Combat Evolved, which was just so revolutionary.
The first time I played through that game, neither my brother nor myself knew about the Flood...that was the coolest twist in a game ever and I can't think of a gaming moment that tops it.
Edit: Shortly after I moved to the DC area (I was reigning state champion of Delaware), my brother and I assembled and "trained" a team in the first Halo game for Lan play. 16 people, 8 on 8. Our eight guys played Capture the Flag at Blood Gulch. One flag to win.
My brother ended up scoring the flag after a painstaking 56 minute round. I had 264 kills and 23 deaths. My brother was probably the second best player in the match overall and he had 151 kills (I don't remember how many deaths).
My twenty-third death was back at our base, after I shadowed my brother to get the flag back there. Someone threw a plasma grenade that, like a boss, I jumped in front of and it stuck me. My brother scored the round and we won.
That was some epic #$&*@!.
-wtk