Mario has been crushing goombas and curve stomping turtles since the 80s. He takes my vote, that crazy mother fucker.

Samus destroyed Phazae, the source of a Galactic Infestation. Galactic. That means she probably killed trillions of Phazon infected creatures.

Lol im not including the killing of aliens.

Commander Shepard if you went with a certain ending.

Surprised that Zanza was only mentioned once. Though I guess that's taking the question a little bit too far.

Probably Dynasty Warriors characters. They just rip through 1000 man armies faster than I can mow a lawn. Seems like an apt comparison :P

Chin wins then.

The glorious Psilon Commander wiped several intergalactic empires with billions of people in each planet in Master of Orion.

Whenever WoW reaches its final expansion against Sargeras (don't think he's actually been in a game yet) I gotta imagine he'll top this list, but his underling Kil'Jaedan must be in the running here, both directly and indirectly as the primary strategist of the burning legion.

Still, there's no doubt in my mind that while they may have the most blood on their hands, Mario certainly has the bloodiest feet :p

... Goddammit