I went with Heather to Discovery Kingdom (formerly Marine World) in Vallejo last weekend. We had a lot of fun. They have several roller coasters in addition to the animal displays and shows that make for an entertaining time. I was surprised at how commercialized it was, though. There were ads everywhere you looked. It seemed like everything was sponsored or brought to us by companies other than Six Flags. They even interrupted the whale show for a thirty second Toyota commercial to play on the jumbo video screen!