Mr. Toad's Wild Ride was a classic. As a kid that last section always freaked me out. But I have fond memories of it along with 20,000 Leagues and the old Eastern sponsored IF YOU HAD WINGS ride, which was the predecessor to Dreamflight.
Disney today is a very different experience from what it was when I was a kid. While I don't mind some of the character replacements (e.g. As a big fan of Lilo and Stitch I was very happy to see Alien Encounter get redeveloped to feature Stitch), I do long for the old Disney World experience and get nostalgic from time to time.
Living in Hong Kong now, the Disney park here lacks my favourite experiences from the Magic Kingdom, namely the Haunted Mansion and the Carousel of Progress.