Well it would be Sharpen or Sharpen more. That would be your only options. Those are the only ones that you can use to sharpen a image.
It should have Sharpen, Sharpen Edges, Sharpen More, Smart Sharpen and Unsharpen mask. Those are teh only effects that will do what you want with possibly the best program to do this with.
Every other effect that Photoshop can do is not going to sharpen the image. If you post the image and what you want to do with it maybe we can help more. But until then this is your only option.