I think the best are the original dubbing of :
The 1962's dub of Snow White (re-redub in 2001)
The 1989's dub of Lady and the Tramp (re-redub in 1997)
Pete's Dragon (Redub in 2003 for extended version)
The Black Cauldron (redub in 1998, like in Suede)
The Little Mermaid (redub in 1997 but reincluded in recents DVD)
I have not heard the original dubbing of Snow White, Bambi, Alice in Wonderland and others because they are either lost or kept by Disney and impossible to access.
The only original dub of the 40s that I've heard it's Dumbo, but I preffer the new version with Roger "Asterix" Carel.