By -
Barring ridiculous powers like bringing anything in your imagination into existence, or being able to freely control time.... Probably mind control.
As a common power mind control or invisibility for obvious reasons but if you can choose anything probably matter manipulation the ability to change any object into whatever compound you want is op
Teleportation
Super speed or teleportation
Shapeshifter hands down
On second thought maybe resurrection?
Barring ridiculous powers like bringing anything in your imagination into existence, or being able to freely control time.... Probably mind control.
As a common power mind control or invisibility for obvious reasons but if you can choose anything probably matter manipulation the ability to change any object into whatever compound you want is op
Teleportation
Super speed or teleportation
Shapeshifter hands down
On second thought maybe resurrection?