Ok, ignoring the other silly answers on this board "Don't drink at parties..."
Ok so, I think to avoid hangover you should stay away from harder liquor, the harder the drink the more ethonol it has in it, which is one of the key factors to feeling crap. Wine is ok, but I don't think it is much of a party drink, and it has to be good quality to not make you feel sick while you are drinking it. I think beer would be the best way to go, but a lager (light coloured beer) and not a malt, because malts tend to leave you feeling worse too. I think though that if you are trying to get drunk then there is nothing much you are do about getting a hangover. If you are bringing the drinks just to get maybe a little tipsy a good lager should be enough for you, and is better for parties, because it allows you to be constantly sipping a drink without getting too drunk or stinking of wine of spirits. Don't go with vodka like the other guy said, you wont taste much, and youll be gone way too quick.
Beer is the best party drink. Wines are for dinner parties, formal ones. And spirits are for old men who are depressed and want to get drunk fast.
I'm an Aussie. So yeah, we drink a lot. 4th most beer consumed per person of all the countries in the world. Hmm that's not a good thing. But it does mean being exposed to quite a drinking culture from highschool...