Right now, only USA. Because US Dollar is defacto international currency. That is domination and therefore USA is a superpower.
We have a problem. It's a paradox. If domination was a requirement for being a superpower, the world should have only one superpower at any given time, but history has taught us that there were two; the U.S.A. and the U.S.S.R. neither side dominated the global market, or even global politics; (one reason why India remained so powerful despite its precarious strategic position was because both sides lacked force projection on South Asia. And Hong Kong too was under the influence of only a minor power then, and see where it is now) U.S. could have cut ties with some of its stronger Europe allies and Canada all it wanted and all it would have done was them shifting the buyers of its natural gas (a major commodity at that time. Caused a lot of pollution, too) from U.S. to U.S.S.R. Of course, U.S.S.R. had sufficient natural gas and oil reserves in its territory, but the shift of buyers could have become the lever using which U.S.S.R. could have put pressure on U.S. economy, straining its industry. (they lack fuel, duh) In any case, U.S. was far from dominating the global market, because its economy was very dependent on U.S.'s allies willingness to cooperate; yet, it was still a superpower, because it still influenced the world a lot. So was U.S.S.R. also. I don't really know where you get the idea that domination is required for being a superpower, (not even Wikipedia says that lol) when there is the term 'dominant superpower' precisely meant for the kind of superpower that U.S. is now. And even now U.S. is far from completely being dominant in the economic and the political arena. In the East, it's China, Japan, South Korea, and India who control economy and regional politics, not U.S. (just don't get started on 'U.S. fleets defend Japanese airspace', it will be tiring) Even if USD crashed down due to mysterious circumstances (alien invasion, for one) all the world needs doing is to change the de facto international currency from USD to Euro and relocate their major establishments from the American continent to Europe and China. Conversely if either China or E.U. was disintegrated we could shift our attention back to U.S., or just make each countries fend for itself with their own regional trade. (Russia-South Korea-Japan can work rather well, and so can Gulf states-India relationship; both will have enough fuel and industry and labor to survive without the West) A feat easier said than done, yes, but hardly impossible, and it proves that U.S. is no more dominant than E.U. or China is. So there is no '*poof* fucking gone' happening when U.S. is gone, despite it being a superpower. But it's still a superpower, yes. The most powerful one. Even if it wasn't, it still is.
Now, the point is, if U.S. can cause such global instability, can other countries do too? Definitely they can, and those includes India (250 billion USD global market share) and South Korea (400 billion USD global market share). It doesn't matter that those countries' shares are 15%-25% of U.S.'s, as long as they have the capability to blackmail the global market
'meet our demands, or we'll fuck you over'. Remove either of them from the global market and the world will go apeshit over where else to get those lost 250 or 400 billion USD from. Aside from that, the impact on the high-tech market will be particularly great when South Korea is removed because it will increase the demands of high-tech industry in other high-tech exporters significantly (I'm not joking) and therefore cause inflation in a worldwide scale, and that's the start of next recession.

Where do you think Airbus get its avionics spare parts from for their airplanes? U.S.? On the other hand the loss of India will cause deflation in the Gulf states' oil and gas revenue and steal Canada's throne as the main oil exporter in the West as those minor Gulf exporters rushes to sell its oil and gas in the Western world. Now there it is, India and South Korea are major powers of the world economy, with the potential to change global economy as we know it, either through action or inaction, rightfully deserving their titles as economic superpowers. Don't get started on the individual members of the E.U. and Russia and Japan; their shares in the global market might seem small compared to U.S.'s, but their loss is still going to be catastrophic. You can choose believe me or not, I don't care. I believe that the countries you believe are great powers only are in fact superpowers in their respective arenas, and Wikipedia is not going to convince me otherwise.
If you are wondering where I got my 'market share' data from you can try the international monetary fund website aside from EconomyWatch. Its credibility is proven (it's an international organization) and it has a lot of articles that can provide additional information.