Well, I play games for three reasons. One reason I play games is because it is a from of escapism to me. Playing games, for any period of time, whisks me away into a different world so that I may momentarily forget the complications of modern teenage life.
Another reason I game is because gaming engages my mind and helps me learn new things. Believe it or not, I've extrapolated many important lessons from games. I've taught myself the entirety of the Butterfly Effect by playing Fragger at Armorgames, and learned to be a being of necessity by playing numerous RPGs such as Fallout and KotoR. I've figured out, by playing a life sim from '86, that my personal problems are not because I don't try hard enough to be good, but because the paradigm I follow is flawed in the sense that it is too linear.
My final reason is that playing games is fun. Seriously, after a normal day of school, there's nothing more fun than a game of Total War or a few rounds of Team Fortress.
EDIT: Sorry for dragging any unsuspecting forum browsers through that poorly written tripe.