I don't really get bad hangovers, when I do it is because of some truly epic drinking the night before. That said I've exhaustively tested a few cures and found that what works best and About.com has a great article on the biology of a hangover, but the core issues to deal with are low blood sugar, loss of electrolytes, and dehydration, hence the old standby of aspirin and a glass of water before bed. My best hangover cure is a fairly straightforward adaptation of that, I'll pop a couple of aspirin, drink a 32 ounce Gatorade (my favorite is the arctic blue cherry but I believe it was a limited time only flavor) and apply tiger balm to my major joints as a bit of preventative care. I'll keep another 32 ounce bottle on my bedside for drinking when I wake up throughout the night (hooray insomnia).
Usually that is enough to ward off any symptoms, but if that doesn't work I usually make myself an omelet and bacon, with black coffee, the mix of proteins, carbohydrates and caffeine takes care of any lingering doubts my body is voicing about this whole "being alive" business and I get to go on with my day. Just a little tip from me to you, dear readers, after the 4th, hopefully plenty of you find it works out well for you this upcoming weekend!