When King's Island first looked at building what would become the Beast the park originally planned to build a clone of concinatti Coney Islands famous Shooting Star.
While clearly this changed (the shooting star was eventually bought back at Canada's Wonderland as Mine buster) Kings Island could have been a very different park with a different out and back woodie and a Togo racing coaster.
Although I assume the same is true of any park. There must be tons of plans for unbuilt rides out there that we will never get to see.