Assassinated By: Commodus, his son
Cause of Death: Suffocation
In the undeniably dude-approved Gladiator, Russell Crowe plays Maximus, a noble and barbaric warrior any guy would love to emulate. And then there's Commodus (played by Joaquin Phoenix), the loathsome crybaby son of Emperor Marcus Aurelius. He's such a waste of space that his dying father flat-out tells him to his face that he's not fit to claim the throne.
So what does Commodus do? Well, besides pouting like a little girl whose Barbie dolls have been stolen? He suffocates the emperor while giving him a hug, leaving the seat of power to his name, since daddy hadn't told anyone else about his plans to empower Maximus yet. It's just one of the many reasons why the sight of Maximus whooping Commodus' ass before killing him is so damn gratifying. Couldn't have happened soon enough, and to a bigger tool.