Gaming in the Children's Department

My library has had gaming events for teens for over a year, but a couple of weekends ago we held our first gaming event for families. Three tvs, three game systems and at least thirty people for four hours. Ok, so all thirty+ people weren't there at the same time. It was awesome. Even better, there were no complaints. (Having set up in front of the building I expected a few.) Hopefully, this will be a regular event; lots of people asked when we'd be doing it again.

• Moms and dads played with their kids, trying new games and new systems. It only took one frame of Wii bowling for one mom to say, "We have to get this." Hey, as long as they keep coming to the library.
• A three year was already quite proficient at Mario Kart. I'm not sure if I'm impressed or disturbed.
• Guitar Hero was hugely popular, and once again I didn't get a turn so I still don't know what all the fuss is about, except it has awesome music. (So much better than DDR music.)

Do you have gaming events for younger kids and/or families? What works? What doesn't? What are the most popular games?