I got two I think would be cool.
One is the power to freeze and unfreeze time. (I feel like complete and absolute control of time would be to much responsibly. (freezing and unfreezing time is already a hand full.))
This power could be pretty fun.
I could go into a library freeze time and learn as much as I want within the second, (Though it would feel like hours to me.)
I would also stop criminals in on of the many ways.
If he charges at me I will freeze time, and move him in front of a wall and unfreeze time.
If he has a gun I would freeze time and take the gun out of his hand and watch him freak out when I unfreeze time.
Also if I wanted to act like an ninja I would carry smoke or flash bombs with me,
then I would throw them on the ground and freeze time, then leave the area and unfreeze time.
Yeah, that would cool.
But like what Orodrist said, with a power like this the responsibly would be a bit to great.
I will post the other super power I would like in another post.