In a Call of Cthulu game from a while back, I role-played as Hannibal Lecter (a 1920s version) and the game began with me being released on a mission to work with another player. That player was kinda fooling around and not playing properly, so he started messing around with me and hitting my head against the wall while I was still handcuffed (we were on the mission by this point, in a small western town). He stole some of my things and left me there to die while he went to do the mission by himself, meanwhile I picked the lock on my handcuffs, picked the lock the house to a door and entered. It was late at night by this point, so I was able to sneak in without being seen. Inside I opened a door to find what looked like a married couple lying in bed together. I use my Martial Arts skill to silently slit their throats with a knife that I started with. After that, I went into the next room to find a small boy who, in the complete darkness, asked me if I was his father. I rolled for Persuasion skill and landed a crit, successfully convincing this newly orphaned child that I was indeed his father. I took the kid on my shoulders into the kitchen, with him cheering all the way. I then opened the oven, threw him in, locked it with a chair and turned the heat up to full (apparently neither the DM or I realised that such ovens didn't yet exist in 1920). After that, I went into the living room and listened to some smooth classical music on the radio, accompanied by the sharp screams. I spent the night in the family's marital bed, beside the bodies.
In a D&D campaign that is still running, I am playing a halfling rogue. At one point, we got a quest from some minotaurs to sneak into a human military camp and assassinate the commander. I was elected, as I was the only rogue, to infiltrate the camp and get the job done. I snuck in, after a few successful roles, and made my way into the commanders tent where I found a bed with the commander's corpse in it. I'd been beaten to the job, somebody had slit his throat before I could get there. Now, no one had seen me come in, and I doubted anyone would dare disturb the captain while he was meant to be sleeping, so I figured I had enough to to skin his corpse without being caught. Crit roll - perfectly sliced commander skin. I was quite happy with this loot, but wanted more, so I decided to use my Disguise skill to wear the commander's skin as a suit. Another crit roll. Then the DM had decided that my chosen alignment of Chaotic Neutral was no longer correct, and changed me to Chaotic Evil. Anyways, I used my newly gained disguise to stroll right out of the base and return to hand in my quest. When the Minotaurs saw me they got a little tense. Remember that humans are around 6 feet tall on average, whereas halflings (as their name suggests) are around 3 feet tall. Try to imagine a toddler that had been messing around in his parent's closet. The Minotaurs were quite intimidated by my level of overkill, and asked me to lead the assault into battle as a kind of morale weapon. It worked like a charm, and around half of the enemy army ran in fear at the site of me wearing their captain and the Minotaur hoard charging behind me. This made it a fairly easy victory. Later I went back to the Minotaur camp and fashioned the skin into a +10 intimidation Cloak of Humanskin.
This post is starting to amass size, and I can't be bothered typing a whole lot, so here is a short list of other things I did in that campaign.
- skinned an entire family (including kids) and shoved their detached body parts into an oven.
- Accepted a quest to find a missing child, found the child, skinned the child and delivered the skin in a package to their doorstep.
- cut a hole inside a hooker and slept inside her Ton-ton style.
IRL: I have never been in a fight, become ill at the sight of blood and disagree with the freedom granted by American gun laws. So why do I love all of those things in games? Well, because they are all very mechanically fun game elements, and thinking up the most ridiculously gruesome story of child-skinning psychopathy is very, very fun. Also, I have little empathy for characters that aren't fleshed out in any way (no pun intended) and never have any meaningful dialogue, which is exactly what all D&D characters are.
Sorry for any un-desensitized people that were in any way offended or disturbed.
TL;DR: Fucking yes.
EDIT:
Just thought of Red Dead Redemption, a game with a completely out-of-place morality slider. Being evil just makes no sense with the cutscenes in the game, which aren't dynamic to suit whatever personality the player might want Marston to have. I played a good guy in that game because Marston was just unlikable otherwise.
I also sometimes prefer playing a good guy in games, just depends how I feel at the time. Although, the only game that made me feel genuine guilt was Deus Ex: HR. Being a bastard in games usually causes NPCs to react terrified and for the guards to come at you, but HR had NPCs that you liked, who didn't like you back, and that made me feel upset. From what I hear, Mass Effect does something similar, but I actively detest that series for a multitude of other reasons.