Bunnyhopping has spawned different game modes in counter-strike aswell, separate from competitive play, including mainly kreedz's kz [0] and bhop[1], which are really really very hard by themselves and a lot of fun. I really like bhop in particular because there's a meditative thing to it.

Surfing [2] was another kind of emergent behavior in counter-strike, I believe, where players can slide through slopes in a certain way and also gain speed plus air strafing.

0: https://www.youtube.com/watch?v=wMIbJbQ2iHc 1: https://www.youtube.com/watch?v=BXs0rFitP54 2: https://www.youtube.com/watch?v=BXs0rFitP54