What song should I sing for my school bash?

I had decided to sing Someone's Watching Over Me by Hilary Duff and playing guitar along side in the upcoming school bash where the seniors have to organize a program for the rest of the school but some bitches heard me and told the teacher they'd be singing it. So now I think I'll sing Back To December by Taylor Swift or Bleeding Love by Leona Lewis but these songs are neither as inspiring nor as good as the former one. Please suggest some songs that I can sing which are Better than Someone's Watching Over Me or maybe similar.I would be very grateful. Thanks,