My opinion for each park:
The original 7DMT without the removed track sections, a real mountain, would have been a home run. As it stands, it's just a good ride. A full Space Mountain refurb would have been a home run, too. The last true home run was Splash Mountain.
For Epcot, it has to be Soarin'. Otherwise, Epcot has never had a home run. I loved WoM, Horizons, and Journey into Imagination as much as anyone, but they didn't hold a candle to the real Magic Kingdom E-ticket attractions. Mission: Space was a much better ride before it was tamed down, btw. A simulator ride can never be a home run, but those first few months were intense.
Tower of Tower for DHS. No question, hands down.
Countdown to Extinction was absolutely a home run that first couple of years. All the light and sound effects, combined with the more intense vehicle, scared me that first time. It's been so tamed and broken down now that I can basically sleep through it. Kilimanjaro with the story line was a home run, IMO. Getting that close to that variety of animals with no fences or glass is really taken for granted by frequent Disney guests. Plus, that last bit got a little rough before rescuing Little Red. I hope we can get some of that back with the Night Safaris. Everest was a home run originally too. Broken effects have hindered it, but it's still a great ride.