Super speed + super intelligence because there is no way your brain is going to be able to process everything that fast without some extra brain power.
What I would really want is the ability to understand any system just by looking(?) at it. Machines, anatomy, organizations, people's minds... well, I can imagine that being considered "overpowered," but I would totally take it as far as it can be allowed to go. That would be really neat, I think.Or this, because it would be amazing.