Well, I haven't ridden Winnie-the-Pooh and my last ride on Mr. Toad was circa 1988, so it's really down to the "watered down" Snow White, Small World, and Peter Pan.
When I was a kid, I remember Snow White scaring me snotless, Small World fascinating me from all directions, and Peter Pan taking my breath away. Nowadays, Snow White is amusing but not terrifying, Small World is horribly rundown (and super irritating to my 21-year-old sensibilities), but the flight over Neverland is still nothing short of magic.
Hands down, it's Peter Pan.