Kids of all ages (yes, adults, too) can't help but enjoy themselves at Six Flags. Sure the price has skyrocketed over the years, but if you make a day of it, it's not so bad. The park is well-laid out, but massive, so it's easy to get separated from your friends. I particularly like the water park, where I can plop my bones on an inner tube in the lazy river, going round and round on a hot summer day while the kids are running themselves ragged on the rides.
They even offer a variety of foods, which I like, as opposed to EVERYTHING being fried and/or loaded with sugar. It's nice to see some healthy alternatives for the grown-ups.
Take the kids--they'll love you for it.