I have 3.
1. Drive 90mins to pick up a game, only to get there and get a puzzled look when you ask where the keys are to take it apart.
1a. Not asking if they have the key before leaving the house.
2. Driving 5hrs one way for a game you've never played, only to get home, fix it, play it and realize you hate it.
3. Over paying for a game because you have to have it, only to have one in better condition pop up a week later much closer.