Any super power, any superhero.
Well, the latest superheroes that have left an impression on me were "The Incredibles." (The movie was a classic, nastalgic in some ways.) I would love to be able to move or stop any physical object no matter what weight, disappear on command, run like Sonic the Hedgehog, stretch at any length, or even go mad when in danger.
My favorite of those: disappearing. Some days I just want to because I'm either too embarrassed to be somewhere or would just rather not be seen, period.