I'm partial to speeddemosarchive.com, because I used to have a friend do serious work on there. Yoshi's Island, I believe Sonic 3, and a few others are his handiwork."Trihex" is is handle. Unfortunately, we're not close anymore. He streams pretty often nowadays.
When he was just starting to get into it big, I watched the Ace Combat 4 speedrun (single-segment, so a complete play-through without breaks/saves), and was convinced I could do better, since it's one of my favorite games. After a bit of practice, I managed to get solid strategies for all the levels, and tried my hand at it. I believe my final time was something like 10 or 12 minutes faster (current record is 2:25:48), but I recorded it on a lower video quality than they normally accept, and so I wasn't able to submit it. I just got lazy and haven't done it since, although I've been thinking about it again lately. As a bonus, I even did it on a difficulty level higher (easy as opposed to very easy).
Besides that, a local arcade in a mall held a Super Smash Bros. Brawl tournament two weeks after the game was released, which I managed to win, using...Marth, I believe. It was nice because the previous tournament I had attended was a SSB Melee tourney; that tournament I lost in the finals to a fellow named...Donald. In the SSBB tournament, I faced him again in the finals, and took it. Sweet, sweet revenge.