You guys should really cut it out with the Wii hate. Sure, it has its flaws but so do the PS3 and XBox 360. At least say something positive about the Wii that isn't snide like "it's good for trading to get other game consoles." I don't go insulting and hating the PS3 and the XBox 360 just because it isn't the Wii.
Anyways Halo 3 and Assassin's Creed come to mind for XBox 360 games.
But if you can't find any games on the XBox 360 that interest you or that you find fun, you should probably trade it back if you enjoyed your Wii more.