Healing powers, for sure! The world could use more compassion and the ability to heal would allow me to make a real difference in people's lives. From physical wounds to emotional scars, I'd be there to mend them all.
Sometimes I want to be invisible. But if we talk about useful superpowers, super health and / or so that the body can not be overloaded (even without sleep). Too many hours of sleep per day, and so much could be done)
it would be the ability to instantly understand and communicate in any language, allowing me to connect with people from all cultures and unlock the wealth of human knowledge and expression.