Open Question: Why are my keys sticking?

My keys keep sticking. The keys themself don't actually stick, but when I'm playing games i move one way or another and things of that nature. It only seems to be the arrow keys, WASD and the space bar. But when I play World of Warcraft, (yes, I play WoW, don't flame) the buttons don't stick. I have no idea what to do. Someone please help!