If you approach fish ich like any human disease, the "cure" is going to be a number of things, including all the little things you do as an aquarist... such as:
specimen selection
water quality
food quality
tank mates
isolation or company
antibiotics, copper, magic bullets
etc.
etc.
For example, if your kid had a cold you would give him/her rest, good food, antibiotics, herbal remedies, chicken soup. If anyone, even a doctor, said to you: "this one thing is the cure, if you give it he/she will be good as new tomorrow" you would laugh.
Most of what everyone here is saying has validity. I dont know any experienced aquarist (like 10+) years, who really stress out about ich. Sure, they will still lose a fish here or there, or even have a tank outbreak, but its not that first date feeling of death anymore.
More blah, blah, blah from me...