Macbook is frozen at startup screen

I was playing Minecraft and was on Skype at the same time one day, then my laptop froze. I had to turn the laptop off using the power button. When I turned it back on the screen froze on the Apple icon and gray spinning wheel.

I've already tried using the Mac OS X Install DVD, safe boot, and PRAM. Anyone else have any other suggestions? It would be very much appreciated. Please and thank you :]