It could be any of your choosing. And might I add choosing wisely, as you won't be able to go back on your answer once it's already been said.
Now, as for what power I would choose, it would be between either indestructibility/invulnerability or superhuman speed (ability to run over Mach 10). But if you bond and gagged me and made me choose, I'd have to go with the indestructibility. Being immune to blunt force attacks and penetration would sure as hell come in handy in everyday life!
I would pretty much be virtually immortal as I could survive things such as bone crushing falls, car accidents, devasting blows to the head, and much more.;)