Energy manipulation. This is intentionally vague, but whatever parameters and limits you set on it, it works out pretty well.
If I had unlimited powers, I could create a wave or an explosion of any energy (such as heat, sonic or kinetic) of any size (stronger than an atom bomb, or softer than a breeze) anywhere I could imagine, most likely within my field of vision, and in any direction.
Anyone with a basic knowledge of particle physics knows the applications of that kind of power. You could even tone it down entirely and use it to emulate telekinesis, ranged strikes, shielding, or flight. Focusing on flight for a moment, imagine shooting through the air with most of the force applied to your legs and back, all the while projecting a cone-shaped shield in front of you to displace the air so you don't die of hypothermia and hyperventilation.