3. Darth Maul
I probably wasn't the only one who thought that this guy was the best thing about the Phantom Menace. This might have been due to the fact that we barely saw any of him and when we did he was kicking ass, but to me Darth Maul appeared to be pure ruthlessness and rage incarnate, embodying everything the Sith stand for and looking threatening as hell to boot. Because of this I'd definitely like to see more of him, particularly his planet and people as well as his training (there's got to be a good story behind somebody who can move and fight as amazingly as Darth Maul). Once again I'm sure many of these things have probably been covered in the EU, but a story that particularly focused on Maul himself, his recruitment by Darth Sidious and his training would be fantastic. However possibly the best thing about Darth Maul was that he was kicking ass for the majority of his screen time, and naturally this couldn't carry an entire film. I'd be concerned therefore that giving him too much of a story might ruin what made the character so awesome in the first place. Only time will tell.