3. Gears of War (Series)
The Gears of War franchise's trademark gun, the lancer, is infamous for its chainsaw bayonet, which allows you to slice your enemies right down the middle. There was also the slightly-less-bloody-but-equally-disturbing curb stomp, which let you finish off downed opponents Ed Norton style.
In addition to the gory third person combat, there are instances in which you'll even make your way through living creatures (like through the belly of a giant worm in Gears of War 2), which you'll pulverize from the inside out.
As the series has progressed, things have gotten even bloodier, internal organs spilling out of dead bodies and new, weapon specific executions, all of them fairly brutal.
