My best friend and I both like the same girl. What should I do?

This is a tricky one. The best course of action would be to talk to your friend openly. Tell him how you feel about the girl you like, and let him know that you'd like to pursue her. Have him share his feelings as well. It may be that one of you doesn't take your crush quite as seriously as the other, and this friend might be willing to step aside if he knows it will make the other friend happy. Try not to end up in a situation where you're directly competing with a close friend over a girl. This could have negative consequences for you friendship.