Mom almost never plays games. The only real exceptions are the occasional Wii Resort or whatever it was called. She doesn't find them interesting.
Dad is a bit different. He doesn't like casual games, but he recognizes that he's just not very good at most of them. Part of it is eye-hand coordination, but in many cases his mind comes up with solutions to problem that would theoretically could work in RL, but fail in game due to programing limitations. He doesn't feel the intuitive sense of "the game can't do that" that most people who grow up with them develop. So basically, he likes to watch games, sometimes to the point of half-ordering it. Best chore ever, for the most part. He doesn't like turn based games, or anything anime-esque, which means that my little brother and he share more interest overlap. Not that there aren't any we both like. He loves the Metroid Prime series and keeps pushing me to continue Other M (sadly...).