The 70s seem to have had a big explosion of theme parks too!
80s gets the next prize due to the creation of EPCOT and DHS to name a few
BTW, there are two Marriot's Great America(IL and CA). I think they both opened around the same time!
And Anthony you are right. Both parks opened in 1976. I was referring to the Great America in Santa Clara, CA, the one Cedar Fair/Apollo now owns.
Seven years later, following the tumult of the Disney company's leadership shakeup, the WDW resort broadened its offerings significantly, with expansion that included a huge water park, a series of new hotels, nighttime entertainment, and a third theme park. All this happening at a time when Disney's service standards were at their highest.
Beyond WDW, the 1980's saw one of the most significant movements in destination parks: Universal Studios Florida. Although the park didn't debut until 1990, its announcement and mobilization had palpable effects, employing hundreds of non-Disney/former Disney designers and engineers and creating real competition that, in the end, resulted in Disney no longer in the "world's only superpower" position.
The 1980's saw all kinds of new attraction concepts that are (for better or worse) standards today. Cedar Point debuted the Magnum and, with it, the hyper coaster. Wet'n Wild debuted the Lazy River. Disneyland opened Star Tours and demonstrated what could could be done with simulators.
And, bringing it back to Disneyland, IMHO, the late 1980's were a golden age at that park, with the attraction count high, operating hours long, and management focused on the guest experience.
The 1980's rock!
My vote goes for the 70's, when the industry was truly nationally reborn and the boom started. Disney World was born. Busch Gardens expanded, Six Flags and Taft Broadcasting (Kings Island, Kings Dominion) both made their mark on the industry around the country, and the roller coaster made a comeback. Other parks that survived the industry downturn started investing a lot of money and expanding. The 80's and 90's were a continuation of the 70's for those companies.
IOA and DAK are two of my most favorite parks. And while I loved Marriott's Great America (when I lived in Fremont), Busch Gardens, and Kings Dominion (when I lived in Annandale) back in the 70's (and early 80's), a world without IOA/Spider-Man & DAK/Everest is not a world in which I want to live! =)
Also, SDC in the 1960's had almost no attractions. Just a cave, a swinging bridge, and a small town with a few craftsmen/women. It really came into its own in the 90's and 00's.