I would go for the ability to freeze time for everyone except me, and also the other way around.
The first on is obvious. I could walk around unhindered into banks, etc. I could also get more time out of the day (I could stop time when my alarm clock went off and get more sleep).
I could also do it for traffic and get places quicker!
The problem with that is aging, so I would also need the ability to slow myself down in relation to the world, or in essence speed up time. This would be useful for times when you're incredibly bored or going places, like in planes, while commuting, in meetings, etc.