Till death us do part in... Skyrim
Nothing says "hard day at the office" like slicing up an entire village of NPCs. You boot up the game, give autosave the night off, and commence to blasting random bumpkins. It's actually rather cathartic, in a Charles Mansony kind of way. You're breaking the game, poking around in the code, and having a good old look at the result. One moment you're the all-conquering hero; lauded by lords and small folk alike, the next you're annihilating a friendly blacksmith with a hammer the size of Stockport. “Charge me for that armour, will you”?
Skyrim takes this rotten premise one sadistic step further, with the introduction of the 'dead thrall' spell, allowing evil-minded folks to raise the recently deceased and compel them into action as henchmen. As with Sleeping Dogs, this system is designed to be used on enemies (in this case, ghouls and goblins), though it also works well with everyday people. For true villainy, players can choose to betray and execute a loved one, before raising them up as spectral servants. Wash, rinse and repeat for infinite torment. Muahah!