What is your comfort video game?

I know someone out there has to be like myself and have a certain game they could play and never get tired of. Something they can mindlessly play and just relax. For myself, it would have to be Fallout: New Vegas. I've played that game vanilla, with mods and modpacks. For me, it never gets old and that hits a certain spot in my brain that just makes it feel perfect to me. No other game I've played has been able to make me feel as comforted than this one.