I second Silverwood, Playland in Vancouver (which has perhaps my favorite wooden coaster), Santa Cruz Beach Boardwalk (maybe the best setting of all American parks), Funtown Splashtown USA, and Lagoon among the many good ones mentioned.
Lake Winnie and Canobie Lake Park are a couple more I’d add.
And though it may not have any big thrill rides, a place called Enchanted Forest in Turner, Oregon is a marvelous little park.