I'd pick up IT...or Legal Studies...or German (or whatever the subjects were called)
IT because I love messing around on the computer and would like to learn more about it properly, and for grades
Legal because it sounds really interesting and a few of my friends do it and enjoy it a lot. It would be a bit of a waste though since I don't want to work in that area at all, but hey, I used to do music and have no skills there...
and German because I'm pretty good at German and wish I'd taken it past year 10 level, and it's really fun and language students at my school get to go on so many cool excursions...