My worst was probably the first time I went out drinking with friends. I'd had a shit-tonne to drink before, and had never hit my limit, so I completely misjudged it, downed a wine-bottle-sized bottle of rum, puked in McDonald's, and stumbled home through what used to be the most dangerous street in Scotland. I then continued to be ill far into the small hours of the morning. The embarrassment was significantly worse than how awful I physically felt (although I did avoid a hangover, thank fuck.) 
Srsly, I'm never misjudging that badly again. Shudder.