1. Manhunt (Series)
For all the blood and guts we've talked about on this list, none of those games have stirred up quite as much controversy as Manhunt. To this day, the game is banned in three different countries for its uncomfortably depictions of violence. Players could suffocate others with plastic bags, impale them with a crowbar and crack their jaws open, or even dismember them with a variety of environmental implements. The game was not exactly kid friendly.
The sequel kept with tradition, becoming one of the few games ever to receive an AO from the ESRB, effectively barring it from sale at most major retailers. Rockstar eventually released an edited version that skated by with an M rating, but that didn't stop it from being plenty violent. We shudder to think what the game would've been like had they released it in its unedited form.