Okami is a good deal of fun, and though it requires you to rack your brain sometimes, if you don't feel like it you can just run around drawing and cutting trees an' . Whenever I feel like popping a game in to just smurf around, I usually throw Skate 2 in, idk if you're into skating games at all, but Skate 3 just came out and it's always tons of fun to just mess around and explore the city doing nearly impossible things on a skateboard (though not Tony Hawk level impossible, mind).