My screen name started with AOL as well. I think I was in high school- must've been 9th or 10th grade. Like Becky, AOL suggested several numbers after my name, but I chose 8989 myself. I was obsessed with the Mighty Ducks of Anaheim at the time, especially Chad Kilger (8) and Paul Kariya (9).
Since I can't think of anything better, I never changed it. I probably should've used 9898 instead since I graduated hs in 98.