Songs I can busk with?

I've got a jazzy soul kind of voice and i love things like mercy by duffy, My Immortal, by Evanescence, Chain of fools, by Joe er, I say a little prayer for you and nature boy. At a stretch, i can sing Fergie. If you have any more ideas for what i can sing that would be great! P.S. I'd like to use them to busk .