Great article that does a good job of explaining why people love of video games. In a nut shell the six moments that make video games worth it are:
1) When you truly feel power for the first time
2) When a piece of “Victory Music” plays
3) The first time you see an awe-inspiring enemy
4) The first time you see the universe running without you
5) Reaching the other end of an impossible level
6) Mastering the rhythm
Personally, I love discovering the trick to a level or challenge and the feeling, oh the glorious feeling, of godlike powers when you’re a high-level character smashing through bad guys. Sooooooo satisfying.