It wasn't until my second year of college that I ever got a hangover. Now I usually get them on heavy drinking nights. They're generally not bad though, just feel kind of in a funk (slight headache and maybe a little upset stomach) for a few hours the next day. My key to avoid bad ones is always to just chug as much water as a can before going to bed. Also, I won't let myself fall asleep if the room spins when I close my eyes.

I've only had one hangover that was so bad I puked the next morning and that was pretty awful. It came after a long night of mixing all sorts of beers and liquors and not drinking any water before passing out. Water, non-greasy food, and time seems to be the best remedy for those.