I don't have any idea what would be my "worst" experience at SDC, but one thing comes to mind.
I was the Marshall for one season back in the 80's and on one particular day, a heavy rainstorm came up suddenly. I was asked to "crowd-control" the Hospitality House because, as you all know, it is somewhat of a bottleneck, being the only way on and off the park. Back then, the cave guide/information booth was still in the middle between the two garage doors. There was, in spite of the rain, a mass of people trying to get in, and because of it, a mass of people trying to leave. Needless to say, it was a jumbled up mess at the HH. After some time, I was able to establish an in-going line and an out-going line, on opposing sides of the booth. These lines stretched for a good distance on either side of the HH. People were moving smoothly along until a girl, I'd say about 14 or 15 years old, tried to buck the in-coming line. One person fighting against a flow of people five or six wide, you get the picture. I tried to encourage her to get into the out-going line, but apparently, she had somewhere she had to be in a hurry. She started calling me every name in the book as I continued to tell her she'd have an easier time getting out in the other line. But she finally pushed me aside and continued against the flow. Well, my frustration got the better of me and as she disappeared into the on-rushing mass, I called after her "OK, be a b..tch if you want to." Well, the crowd that was around and had witnessed the whole debacle cheered and clapped when I said that. Admittedly, as an SDC employee and the Marshall no less, I shouldn't have done that, but it is what it is. Anyway, after 20-25 minutes the mass of people eased to the point that I was able leave, so I went directly to my supervisor and told him what had happened. He said not to worry about it, that he'd take care of it if any complaint came about due to my indiscretion. Sure enough, the girl's mother came and found me about an hour later and complained that I had called her daughter a b..tch. I explained what had happened, and that I hadn't actually called her one, but merely that she could be one if she wanted to be, as in, it was her option. She was somewhat mollified after my explanation and apology, but still wanted to see my supervisor so I pointed her in his direction. I never heard any more about it, so I guess he handled it, or she decided not to pursue it further.
That was probably my worst experience with a guest, although when I worked as the Saloon crowd-controller, I had to step between fighting guests several times to ease tensions that arose when people tried to cut in line. We employees are there for the guests, but sometimes they can put us in very sticky situations. In spite of that, we still love 'em all.