What decade do you think WDW was at it's best?

I would say, in my personal opinion 82'- 88' These were my teenage years and Disney seemed to have everything I needed, without being overcrowded or overwhelming. You could go for a week and see the majority of things, plus have a couple of non-park days. It made for a fun vacation without being rushed or trying to pack in too many things into one trip. My reasons include the things you mentioned with the exception of MGM.

I'm going to say 2020's.

I love nostalgia as much as the next person and Disney nostalgia & history? I'm all in. Unfortunately, I spent exactly 7 days at the parks prior to 2003 and I was age 9-10 at the time, so my personal memories of those times is spotty at best. Though I do remember (and LOVED) Horizons and I don't remember details about the original Figment ride, but I remember loving that as well. I also loved the characters in space suits. In general, I loved Epcot. Beyond that, my memory of bygone days of Disney is full of holes.

I chose a future decade because I am immensely excited about some of Disney's looming projects and so far, almost every time they've taken away something I've loved, they've replaced it with something that I love equally if not more. (Notable exception: Mission: Space replacing Horizons. I can't even ride MS--not even the green version, but it does look cool and I love space stuff.) I love that Disney stays true to the idea of being ever-changing. I loved Snow White's Scary Adventures, but I also love 7DMT. And Disney is so great about honoring it's history--like using the old witch in the new ride or like the picture of Mr. Toad handing the deed for Toad Hall to Winnie the Pooh--that I trust them to leave the brightest beacons of nostalgia alone when considering "improvements" for their parks.

My first visit was in 2005 when I was a slightly less old fart than I am now. You know, it's all good. The best time is whenever you get to go.

Definitely the 1960's. It wasn't as crowded and it was so quiet.

Way less crowds.

I think I would have loved to have gone during the 80's. Like right after Epcot opened in 1982.
Way less crowds plus my favorite parks are MK and Epcot and those were the only two that where there. They had the characters in their space suits. Then I feel like it was at a height technologically then too some of the stuff is now outdated.
Plus you could stay at the Poly or Contemporary for fairly cheap. I would love to have gone then, alas I wasn't even thought of because I wasn't born until 1990.

This cracked me up! My first visit was in 1999, so I was a 30 year old "old fart". Any time I get to go is the best time for me too!

Every thing is relative. My first visit was opening weekend in 1971 so does that make me an old fart. I was 35 at the time.
Joe

Yes! But still young at heart!