For me it's 500mg of naproxen (2 - 2.5 Aleve will work), a multivitamin, and some gatorade.
Also, I have bad discs in my back, so it's not uncommon for there to be some good opiate based pain pills in my medicine cabinet either. They really don't take the hangover away, but 15mg of oxycodone makes you not really care that you have a hangover.