I find it funny when non-alcoholics rhapsodise about how you can avoid a hangover. If you want bodybuilding advice, you ask someone who has lots of muscle. If you want hangover advice, you ask an alcoholic. EVERYTHING in the right quantities gives you a hangover, a hangover means you perform poorly in the gym. Alcohol is a sedative, and when you're shifting iron you want a stimulant.
After a big night I feel like crap in the morning, I still force myself into the gym but my performance is half as good at best. There are many studies that link alcohol with cancer and heart disease, but it is hard to beat several cold beers on a hot day and a holiday from your brain