I would sing "Every Rose Has It's Thorn" by Poison, and if It was a night where I get to sing two songs, my second would be "Good Love." By Poison.
But, If they wanted something more mello, I would sing "Crazy For You" By Madonna.
If they wanted me to go way back I would sing. "I Wanna Be Free" by Davey Jones or "My Little corner of the World" By Marie Osmond. (But, I think Eddie Arnold sang it first)