My parents don't mind me playing anything at all. My mom will sometimes comment "I don't like that game" like she'll comment about, I dunno, a SAW movie (or any other crappy all-gore movie). I played Hitman when I was 12, the 3D GTA games at about the same age, and I turned out fine. She even asked me, very politely and genuinely interested, about the sex scene in Mass Effect, which she witnessed.
My fatehr doesn't play any games, but enjoys watching me play and commenting on the graphics and some featuers he thinks are cool ("Oh, you can team up with people? That's great"), while my mom loves World Of Goo, Peggle, and is totally addicted to Plants Vs Zombies.