One single superpower, or a suite of powers that exists within a single character?
Assuming that we're talking conventional media (e.g., not religion), and we're talking about powers that exist within a single character, I'd probably take the powers of a witcher, from Sapkowski's novels. They're not immortal, but they live multiple times longer than a normal human. They're not invulnerable, but they're able to take more physical abuse and heal than any normal person. They're able to use magic in a limited way. They move faster and are stronger than humans. So they're not so far outside of humanity that they can't still blend in with and appreciate humanity.
I feel like most other super powers would quickly lead to intense alienation, because you'd be so far outside of the normal human experience that you'd lose the ability to empathize.