For me, the girls were almost 45 mins late for the service, myself included. This was because the hairdresser had double booked and we were all sitting there waiting on me to get my hair done.
Then once we finally got to the church, half way through the service my sister (maid of honor) had to bolt to the minister's office because she had to be sick. She was throwing up in a wastebasket, and those sitting in the front rows could hear it.
It was a winter wedding, and we absolutely froze through our pictures being taken. It was supposed to be a nice day, so we had outdoor photos. The day took a turn for the worse and ended up blizzarding, and we had to cut it short. I didn't end up with a single photo of myself with my family.
The absolute tipping point was during the reception. We had an open bar, and some of the in laws got very drunk. They were loud, roaring, laughing, then all of a sudden a scream. Uncle in law had a stroke. Literally. He was stone sober, just bad luck with the stroke (he is doing fine, no ill side effects and fully recovered). Father in law did not know that he was sober, and himself being quite drunk turned to me and blamed me for killing his brother by giving him unlimited free alcohol. I ended up spending my wedding night crying in my very expensive hotel room and not wanting to do any of the things couples should want to do on their wedding night. I honestly should have gone to the courthouse the next day and asked for an annulment, because in every possible way the powers that be had tried to show me that marriage was a mistake. My friends have a good laugh about it now, and its a running joke that no matter what they worry about happening at their weddings, it can't possibly be worse than mine was.