Good theming to me is something that makes you feel like you've walked into a whole new world and not just an amusement park. Take places like Busch Gardens, Universal, and Disney for an example. Or even Kings Island in it's earlier years. I tend to have a lot more fun at parks with great theming, good shows, and family friendly experiences than I do at parks with just tall coasters and concrete. (One reason why I don't want a giga coaster at Kings Island.) I love going to parks with a lot of coasters, but I'd still take a nicely themed ride over a tall,fast ride placed in a parking lot.