Former DJ here. Most of the best stories are of the other DJ's I worked with for the years I was doing it, but I'll keep those under wraps I am friends with most of them still.
At one club, I was taking a quick piss and looked up at the top of the dividing wall of the stall and saw a chick's fingers, and then the sounds kicked in. Hard sex going on. I finish and walk out, passing their stall's open door as I go and I slow down to get a look because the chick was pretty hot. Drunk guy standing by the bathroom door hits me in the arm and says "Hey, don't cut in line!", and I notice he's jerking himself off watching. At that point the dude actually fucking the girl steps out, also drunk, cock hanging out and is all "What the fuck?!". Girl runs out of the bathroom past me laughing. So 2 drunk guys, pants open, fighting in a bathroom over a chick that isn't even there.
Another night, same club, a guy gets really drunk and keeps requesting heavy/hair metal songs. It's a goth/industrial club, so Skid Row and Poison aren't on our play list. Won't take no for an answer and continues to pester us in the DJ booth. We push him out and close the door. He's pushing on the door to try and come back in, calling us pussy ass faggots from the outside loud enough for a few people on the dance floor and the bar tender next to us to hear. Bar tender signals security who come over to 'ask' him to leave and he puts up a fight. We watch from the booth which is raised so we can look down over the wall to the stairs and see it happening. Drunk throws a swing and a miss, but security backs up and looks up towards me and smiles. All of a sudden, another DJ in the booth calls the drunk through the door and he turns and looks... just as the DJ kicks it. Door to the face, security catches him as he falls, drags him out, dancers all laugh and keep going.
Different club, a guy is too drunk to stand, but keeps requesting old Hank Williams songs. He's clearly from the south and a country boy out of his element in a dance club and all alone. Leans against the wall of the slightly raised DJ booth and slides a bit before he corrects. Over and over. Security comes by and asks if he's okay, trying to find out if he's too drunk to stay. He laughs and say's "I'm good. Besides, this dude needs me." as he points to me. I shrug and have no idea what he's talking about. Security asks again, and the guy continues "I'm holding this mother fucker up." as he points at the DJ booth walls. Just then, a drunk girl trips and falls on the edge of the dance floor, and country boy slurs out "See, gravity's a bitch around here." Security laughs and lets him lean there, where he remains all night long. Closing out the set, I toss on Hank Williams and he stands silent through the whole thing until it's over and just says "Fuck yeah" and walks (as best as he can) out of the club.
Different club again. Super angry drunk guy comes up and tells me the music I'm spinning is shit. Spills his beer on purpose over the DJ booth wall trying to get my shit wet but misses... hits the trash can on my side of the wall which was pretty miraculous. Comes back a few songs later, same thing. This time he reaches and grabs what he can, which happens to be the wires connected to my CD player. The one currently pushing out music. He pulls, music stops and I pull back on the deck. My hands slip and he hits himself in the face with the CD deck and falls down to the dance floor. Everyone is looking over, so I hit a slider, and go to another song, good times resume. CD deck is on the edge of the DJ booth now, and security reaches up for it so it won't fall. To this day I'm not sure if it was purely accident or not, but CD deck ends up falling onto guy's crotch. 30 minutes later security comes into the DJ booth to tell me he's outside being arrested for attempted robbery, and brings me a drink.
Pretty much my time in clubs taught me that you just don't fuck with the staff. First and foremost. Start fights with other patrons, and you might talk your way out of it but rarely. Less so if it's a regular. But fuck with the staff and things go VERY badly for you. Also, bouncers at one club, are usually regulars at other's, so regulars and bouncers and staff all know each other... all over town.
... and yes, I totally got the drunk chick in the restroom's number later that night. It was pretty cool to be a DJ for a few years in that scene.