This is a long story, but I doubt anybody can top this.
My worst gig was when I was back in college. My band got a gig in LAREDO and so we drove all the way from denton, tx to laredo. I think it was about a 12 hour drive. We left super early and got to the venue really early. The venue was a pizza parlor/pool hall/metal bar, decent sound, kind of akward. Anyways we were super early so we decided to walk to mexico. We could see the mexican flag in the air and it looked like it was maybe a mile away. We started walking towards the flag and 3 hours later we realized that the mexican flag was at least 100 feet wide, one of the hugest flags I've ever seen. so by the time we got to the border we had to turn around and walk all the way back. I was wearing converse, and no socks, none of us were really prepared for a 6 mile walk!
So we finally get back to the venue 6 hours later, and start getting set up. Then out of nowhere a freak hail storm happens (this is in march in the middle of the texas desert). Water starts pouring in from the cieling all over our gear, we are scrambling to get our gear back into cases, and the club owner comes in and starts yelling at us to MOVE his pool tables out of the dripping water. We spend the next hour moving everything around while he yells at us.
The city starts flooding, it's pretty clear the show is cancelled. Our cars all got massive hail damage and cracked windows. The club owner tells us the show is cancelled and offers us PIZZA as payment. We decline and decide to drive to austin to stay with friends.
When we get to austin (it's like 2 in the morning, we've been up since 4 am) we go to our friends house and a raging house party is going on. We tried to decide if we should sleep in the cars, but we end up deciding to drive home to denton (probably another 5 hour drive).
It doesn't end there, on the way to denton we pass through fort worth, and the texas motor speedway is having it's NASCAR RACE. the entire freeway is stopped and we sit in traffic for 2 extra hours. we didn't end up getting home until 12 noon the next day.