The name says it all. What do you like in a game. I like the gameplay and obviously the graphics are a must. The action or enjoyment factors are what I want to be high. Good shooters are my favourites.
I enjoy when a game make me flip out with excitement. I enjoy when a game has great graphics and game play, especially a game with great re-play value. I can generally look past a bad storyline, unless, of course, it's downright absurd. But more than anything, I enjoy a game that I can play with my friends. Nothing angers me more when I look at the back of the box and it says "1 Player". Co-op games are the best in my opinion.
I like games that mix things up a little with the gameplay. multiplayer is great but not essential. I like a good plot, but too much exposition dulls the experience. And personally, graphics only have to be good enough that that I can tell what everything is.