Most of my gigs have resulted in some minor disaster or something to cringe over.
One gig in a coffee shop in Edinburgh resulted in a 45 minute set with no clapping and between one song I heard someone say quite loudly 'I wish he would shut up, I'm getting a headache'. On the upside I got free coffee and the best roast chicken paninni I've ever had. Getting no reaction is worse than getting a bad reaction in my book.
I've been wary of coffee shop gigs ever since.
I've also had the string break, string detune, strap snap, dodgy leads, drunk hecklers, drugged hecklers, fighting etc etc etc.
I did have one guy who kept shouting for dead kennedy tunes which I don't do as I only do originals.
It's all a laugh though and keeps the mundane reality at bay for a short while