So you can potentially go as far back as 1989 but what year your first DL trip? If it’s before November 1995 you can do the Skyway. For me the allure of seeing some rides that went to Yesterland that I never got to experience like ATIS and just the low crowds in general is too great to pass up. I’d go with that before the best version of the park or attraction lineup in my lifetime.
If you want to get technical, my parents tell me they took me as a newborn. -and I do have memories from when I was younger of riding the Skyway and boarding at the Fantasyland station, specifically. I also remember loving it as you passed through the Matterhorn. I also remember being horrified of Space Mountain and Pinocchio's Daring Journey.
Believe me, I considered it. -and while it would be fun to experience stuff like the Skyway, original Submarine Voyage and Tomorrowland before it's disastrous 1998 makeover again, I made the choice to think of this almost like.. if I could freeze the parks at a certain point in time and experience them again, when would that "perfect" time be, for me? It would need to be a time where there is more for me to love than for me to miss. So I weighed those types of experiences against more modern (-and still accessible) ones that would vanish as a result and arrived at where I did. So while many would be willing to trade something like HMH or even DCA as a whole for the return of the Peoplemover, I'm not really one of 'em. Though I would trade away something like Galaxy's Edge for Big Thunder Ranch (-and I say this as someone who actually likes GE).