Plenty of gigs done under the influence of far too much beer, and I play like a drain when I'm like that, I just can't concentrate, so the line is drawn under a couple of pints at the most before playing these days.
Years ago when I was the singer in a metal band, we had a gig @ the Iron Master club in Telford. We had a lady from Roadrunner records coming to see us so we were nervous. Long story short, I got hammered, truly hammerd before we went on. Unfortunately she turned up. I got halfway through the set, stood on a table and waved my 3 piece suite in her face, and disappeared into the bogs, with the microphone, while the audience listened to me groaning through the PA before falling asleep on the piss soaked floor of the toilets.
It was a joke, I'm certainly not proud of it at all, and the big shame was the A&R woman thought we were good until the 'table incident', after which she got up and left.