Bad ass. Takes no crap. Has no problem doing what needs to be done.
2. Luke Skywalker
Jedi Master. Defeated the Sith. Read the novels and comics later on. He is the most powerful Jedi over the span of...practically ever.
Pains me to say it. I don't care for Superman that much. However, I can not deny that is one of the most powerful characters ever created. (That's actually why I don't like him that much; he's too powerful.)
4. Silver Surfer
Don't know enough about him. However, I do know that you do not want to mess with this guy.
Simply put: the strongest there is. But he's last on the list because he loses it sometimes. He has the potential to save the world, but also to destroy it.