It’s gotta be Epcot, right? A park that opened with a fully realized concept and has slowly gotten rid of said concept. But it’s a bit harder to say which ride would be best to bring back. Bringing back Horizons could do wonders. As the sort of “thesis” of the original park, it had elements of all the original pavilions and could still act as the heart of the park even as all the other original rides leave.
However, I do think Horizons would be quite dated by now. I would be able to view it as an interesting exploration of the 80s view of the “future,” but I don’t know if your average guest would see it like that. I imagine it would be seen as something that should have left the park back in the 90s. Now the original Journey to Imagination on the other hand was fairly timeless. It had that same feeling something like Haunted Mansion or Pirates of the Caribbean has, where it embraces its purpose or capturing a mood instead of educating about the future. So, while I’d prefer to have Horizons, I think Imagination would be the best fit for the park at this point. But instead we have Eric Idle in “I really wish I weren’t here right now” the ride.