What song do you think Adam Lambert should sing on the finale of American Idol?

I have been Adam's number one fan this season on Idol. I agree he is a bit eccentric and sometimes over the top. However, there is just something about him that intrigues me! Whether he is gay or not gay does not matter to me. What is important is that this is a singing competition and his vocals are mad ridiculous! Each week I can hardly wait for his performance, because I know it is going to be amazing! He keeps everyone guessing and never bores us like so many other contestants. So I keep asking myself what he needs to do to win this thing. Now that Gokey is gone, this helps Kris because all of Danny's votes will go to him. So Adam needs to come out and do it BIG for the finale! Maybe break out on stage in Elvis's white outfit and sing an Elvis song? (I think he looks a lot like Elvis.) Or does anyone else think a Prince song would be a perfect choice for him? Also, does anyone know how many songs they sing for the finale? I can hardly wait for Tuesday when Adam is going to rock my world!