Things that suck at gigs for me are non-responsive crowds, drunken people that try to bum-rush the stage, and people I don't know trying to come and "help" move my stuff after I perform.
*side note*-- I noticed that most of you hate when a singer stands on your bass drum, and as a drummer I understand in a way why you can get pissed about it. I am also a screamer for a heavier band (www.myspace.com/edensrising
) in which I don't play any instruments (sadly) and I've discussed with the drummer about maybe stepping up onto the bass drum for a stage presence effect, and I did a bit of research. The only time you really have to worry about it really messing up your kick drum is when they are either a larger person or they jump onto the drum. Otherwise there's really no need to get all caught up in a fuss about it.
Check out my band Edens Rising at www.myspace.com/edensrising
if you're curious about what I meant by "heavier".