I went to Six Flags Great America (Gurnee, IL) a couple of weeks ago. Prior to then, I didn't go in six years (after going at least once a year for 11 years straight). It was nice to see what they did with the place and experience the brand new ride, which is the best coaster they had in years. My girlfriend and I went on a weekday, so the lines were short.

Other theme parks I have been to:

*Disneyland
*Dollywood