Way of the Pixel had a competition (if you can call it that, since nobody wins) a bit ago to create Gameboy-ized versions of modern games. They're here, and I pretty much want to play all of them. If you can't figure out what one is, just right click and check the image name, that's what I did. There are lots of great ones in there, but I think my favorites are BioShock (left), Phantom Dust (criminally unplayed game), Odin Sphere, Tenchu, and Dodonpachi. Thanks to Frank for pointing it out.