Mario and Sonic: Rival 1 - King Boo, Downhill

#1 - King Boo King Boo is one of the easiest as long as you know what you're doing, which isn't too hard. That's it. Chose Luigi because it was so obvious. That and King Boo chose him right off the bat to race on the DS version of the game. Once you beat him, you can try any other characer.