Billy Crystal & John Goodman as Mike & Sulley (Monsters, Inc.)
Why It's So Special: While Woody and Buzz encapsulate Pixar's heart, Mike and Sulley are the studio's funniest double-act - aptly, given that this is the story of two monsters realising their vocation in life is to make children laugh.
Individually, this is inspired casting - avuncular Goodman, wise-cracking Crystal - but together they're a hoot, due in no small part to Crystal pushing for shared improv time.
Crystal speaks: "I did the first two sessions alone and I didn't like it. It was lonely and it was frustrating... I said 'Why don't you get John in here? We'll do it together and we can do everything you want but we'll do it together.
Then it'll be natural. Then the editor won't be the one who has to put it all together so it sounds real. It'll just be real. Then we did it and it was great."