Winning the Quake 3 and UT2004 1vs1 tournaments. I did way better than I thought I would in UT2004 instagib, because instagib can depend on lucky spawn kills a lot. I played my cards right and did very well.
The Quake 3 tournament was very fun. It was my first Quake 3 tournament. I met Cloud in the Winners bracket finals, I believe, and before the game started, I said "See you in the finals ;]", because I knew me and him could beat everyone there. I beat him, sent him down to the losers bracket, where he beat my teammate, buu, and then I took him down in the finals.
Also considering it was a 100 man lan, and I won both UT2004 and Quake 3 1vs1 tournaments without being defeated (or nearly close to it, not to brag ;] )
s2i also took the UT2004 CTF 6v6 tournament. We won both of our matches within 2-3 mins ;] I taught them how to play some hardcore defense, and it showed, because not one flag got far out of our base at all if the enemy grabbed it. I trained a few of them, and HystericPoison commented on how he felt like he was playing so much better during the tournament because of it. I was glad to see that my training helped.