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.
I loved their first album, listened to it a lot. Shinobi vs. Dragon Ninja and The Fake Sound of Progress are both amazing tracks. Unfortunately they’re both vocalized by a literal baby rapist, so it’s hard to rock out to them now. Asshole wrote the tracks too, so I doubt No Devotion will ever cover them.
As for Guns N’ Roses, a friend pointed out something that’s been living in my head for months now: Axl Rose is the Starscream of Guns N’ Roses.