My wife very rarely plays. When she does, she only likes to play certain games (Flash and Avatar, mostly).
My daughter (1.5) loves it. We play quite often. She has her favorites -- Wh20 and JD (my brother's game we temp traded). She's discovered the flipper buttons pretty recently, and tries her damndest to get both of them!
I love playing with her, but her attention span is short. She likes to watch for about 1 or 2 balls, and then move on. I'm looking forward to continuing the tradition with her though. One of my favorite things is hearing my daughter ask me to go downstairs and play "paball".