My pick is Five Finger Death Punch and the obvious answer is Ivan Moody. The guy radiates that alpha-male wannabe energy and it definitely rings through all of the songs he has written and performed with this band. The guy is just a prick and a self-victimizing asshole.
I think he’s the primary reason FFDP is mocked so badly.
It’s when he gets into the “Why does everyone hate me” and “FUCK EVERYONE WHO’S NOT LIKE ME AND CAN’T HANDLE ME I DRINK MONSTER, FUCK EVERYONE RAHHH!!” rhetoric is where he gets really unbearable.