ModestMachina

I'm going to go with Silent Hill 2. It's not outright scary, but it makes up for it in subtleties, like hearing some whispering in the background of an empty room or hearing faint running footsteps heading towards you in the distance when you're outdoors. You're usually not completely frightened in SH2, but you're constantly on edge for the entirety of it.

The first Dark Souls game pretty much lets you kill anyone you meet. Granted, there aren't much in the ways of plot-essential NPCs since most of those are bosses that you have to kill, but you can kill main covenant leaders, shopkeepers, allies, and people who just generally hint you towards the plot. They won't respawn until new game+, either, so it's a big challenge if you decide to go that route.

Figure I might join in. I'm totally up for chatting, multiplayer, and generally discovering new games. I'm kind of up for anything, really. Feel free to stop by. http://steamcommunity.com/id/modestmachina