A study of rats in Philadelphia claims that the easiest way to cure a hangover is so obvious you're probably already doing it; you just continue to relax in hangover pose on the weekends (weekdays? Fine!) because your brain needs the down time. The cure is aspirin and coffee, and the scientists found this out by giving rats hangovers and then trying to take them away.
Thomas Jefferson University in Philadelphia induced the rats' hangovers with ethanol, i.e. "pure alcohol." The idea was to block the chemical acetate, which is produced by alcohol—even small amounts of it—and causes headaches. Caffeine has been used for this purpose quite a bit: it's an ingredient in Exedrin, the headache medicine, and aspirin has anti-inflammatory properties, so paired together, they apparently do great work. Caffeine is sometimes frowned upon as a hangover cure because it allegedly dehydrates the already-dehydrated drunk. But the scientists say the rats were not dehydrated by their hangovers.
The only trouble is that aspirin is hard on the liver, which is "already stretched trying to deal with all the alcohol from the previous evening." So this was a total waste of time: go back to eating spoonfuls of honey and chasing them with bloody marys, or whatever. But seriously, what do you do...that works? Home fries? Green smoothies? Acidophilus? A beer? Vicodin? Rom-coms? All of the above?