Besides all of Jitspoe's hard work of course, is the legends. And by that I mean Legendary Players and Legendary Maps. There are players you hear about but rarely see, some have false reputations, some are just flat out incredible. When I first started playing, the legends to me were Dog, Superman, and H@ze. They weren't that great but to a noob they looked like... well, Superman. And The legendary map-makers, Dirty taco, S8NSSON, RuiNeR, Pimp, and lots more that I can't think of right now.
And then there's the maps themselves. The sheer number of maps out there is mind boggling. When you play, think about the fact that you will probably never even see more than 1/4 of the maps made for this game. Some of the great maps become popular for a while, then fall into the abyss of old maps that nobody ever uses anymore. And then there are the classic maps that never die... I must have played Shaz33 over 9000 times... It never gets old.