I don't know if I've ever had a hangover in my life... even with puking and everything. Definitely never got a headache from alcohol, and usually I feel 100% the next day.
Alcohol REALLY bothers my stomach though. I rarely drink, and when I do even the first shot can make me feel like vomiting... then I put down five more and feel fine

If I stop around 5 or 6 that's good... usually I'm none too careful, however.