My wife and I go biannually to Dorney Park in Allentown PA, and it's honestly one of my favorite theme parks to visit that isn't Disney.
We go in the Summer for Wild Water Kingdom, and in October for their Fright Night, and it's always a great time. Their water park slides are fun and varied, and their Haunted Houses and Fright Zones are very high quality and well made, since they're permanent buildings, not pop up tents or converted warehouses like what Six Flags does.
Ride wise, I feel like they have a good variation of coasters for everyone. Steel Force, Thunder Hawk, and Demon Drop are solid entry-level coasters for people who don't like major thrill rides, while Hydra and their new Iron Menace work as great stepping up stones for more inverted rides, and of course, Talon and Possessed are there if you want your ass kicked.
The park also has a lot of the older style carnival rides you don't see too often, such as an old school spinny swing ride, a very quaint and traditional styled Ferris Wheel, an egg scrambler and Wild Mouse, and a pair of great Water Flume rides.
So yeah, if it isn't obvious I absolutely love Dorney Park.
you think dorney is better than great adventure? they are kinda close