My older brother who is 26 has never really liked video games... at least not as much as I do. I think he once had a Commodore 64 (sp?) way back when he was a kid, but that's probably the only gaming experience of his life. He's never seemed too interested in any of my video games and such.
My little sister who is 11 is another story, though. Because of me - or at least so I'd like to think - she has a GameCube and is more or less obsessed with Super Mario: Sunshine and Super Mario Kart: Double Dash, which are both good games. She also has some interest in some PC games, especially The Sims.