The most frustrating hands in blackjack are the following:

when you have an 11, double, get a nice picture with a big bet out and the dealer also gets 21.

lower your bet then get a blackjack.

get a blackjack with a big bet out, and the dealer also has blackjack. (when you didn't take insurance)

double on a 10 get a 10 with a big bet and the dealer gets 21.

not winning with a 20, with any size bet.