Hmmm....I have a few.
Drive through operator at a fast food restaurant:
Minimum wage pay, you get blamed for EVERYTHING that goes wrong (if the cook puts on mustard when you typed no mustard, it's your fault---so thinks the customer, etc) and people treat you like shit. Once I had a guy compliment my watch----literally that was the highlight of my entire week on the job.
Door to door salesman for Kirby Vacuums. I was 18, saw an ad in the paper promising 450 a week for "set up and displays" basically, demoing a product for a potential customer. It was they took 90 minutes per showing and I had to do 15 a week. I added it up and it was better than I was making at the fast food place, so I applied. Guy interviewed me, said I was hired. Turns out, I had to go door to door requesting to do the demo for this $2000 dollar vacuum cleaner. Needless to say, I was lucky to get 2 showings in an 8 hour day. I quit after 4 days.
Last terrible job I had was working as an Amazon "Picker" in their warehouses. You have this scanner thing, and you walk around up and down the place to the aisles it tells you to go, "pick" the product, and place it on a conveyor belt. 10 hour shifts, it was exhausting. Great exercise, but the pay was about $10 an hour, so not worth it.
I don't regret any of these jobs though, because at the end of it all they are what inspired me to work for myself!