Which superpower?
Personally, I choose America, cuase we're the best. But India and the European Union are looking pretty good. China would be cool, but they're just a little too harsh for my tastes.
Russia sucks!
Also, by what criteria do you judge this? For me, it's too broad.
But there's most powerful, most best (according idk, morals and shiz), the one you want to be the most powerful, and so on and so forth.