15. Portal (2007)
This senior thesis cum sleeper hit showed that students could hit it big in the games business — not after years of obscurity but immediately. But the space-bending puzzles of Portal will also have an influence on the way games are sold. Valve could have padded out the four hours of gameplay with extraneous cut scenes or boss battles, but instead it let the game be concise (and a bargain at $20). Portal proved that quality can trump quantity. –Daniel Feit
I could play Portal for hours and hours. I loves me some CAKE! Even if it's a lie.