I used to think I was low maintenance with dice, until I needed to buy emergency dice to run a game. The store didn't have the regular Chessex ones, but I'm not a brand loyalist, so I grabbed whatever.

The numbers weren't laid out properly. You know how opposite sides (apart from the d4, obviously) sum up to one more than the die size? I.e., opposite sides on a d6 add up to 7, and opposite sides of a d20 will add up to 21. They didn't do that. Bugged the hell out of me, and I still consider them cursed.

So yeah. Even though I'm not as particular about my dice as most players, but there are some dice I find unsettling and will not play with. :P