Hardly the worst bad beat ever and i wasn't actually in the hand (was waiting for BB) but:
Flop comes 5 T A. First guy raises, 2nd guy reraises, 3rd guy goes all in and is called. Turn comes and the other 2 guys go all in. Turns out they had 55 TT AA and all had flopped a set...was only .1/.2 blinds and the pot was 50$ or something haha