Worked there years ago during 2006-2009 ish.
An adult guy came in a traded in a bunch of Game Cube and PS2 games. One of them was a Mary Kate and Ashley game. The cases were clean but we always wiped them down. When my coworker got to the MK&A game I guess the windex caused some sort of reaction because something came back to life and smeared all over the case. We threw the case away lol.
Another guy would come in and only buy Leisure Suit Larry games and the Dead or Alive Volleyball games.
We used to play the console testing TV from the back room lol. It was a fun job but some of the regulars. I have a lot more lol.
Source: https://www.reddit.com/r/AskReddit/comments/bicr5z/gamestop_employees_of_reddit_what_are_some_of/em001sj/