I've only had 3 that I can remember and they were all when I was in college. First one was working in the warehouse of a department store with 2 psychotic old ladies. The first day I left for lunch and never went back.
Second one was being the night janitor at a private high school. I took the job because it paid $15/hr which was huge money back then but it was very humiliating work. At least the kids weren't around to make fun of me at night.
Third one was working for Chemlawn spraying liquid fertilizer on people's yards. I was the "helper" and they would put me with the guys whose routes had the biggest lawns so 2 of us could spray at the same time. Most of the time the guys sat in the truck and filled out paperwork and made me do the whole thing myself. Some of the guys were cool and would help and we would bust out the whole schedule by 1 or 2 PM and then go sit at the bar for a few hours.
The worst part was when you were reeling the hose back in and it would break. The power reeler was run by the same pump that pressurized the liquid so when the hose broke this crap would spray all over you like crazy. Burns your eyes like you can't believe. I'm thankful I don't have to do that crap anymore.