Humans. No matter what happens, they endure. Natural resistance and stubborn nature led them for over 20,000 years, continuously advancing in science. Oh, a fictional race. Ok. I would have to say The Force wielders, from Star Wars lore. They are only ever seen in the comics and crappy TV show, but they have the power to destroy the universe by thought. There is only 3 of them, and the only person who could kill them was themselves. Which they did, aided by the Chosen one, Anikan Skywalker and his mentor, Obi-Wan Kenobi. (Both are humans lol, worth mentioning Anakin was the only person who could auctually hold them off for more than a few seconds.)