In terms of, emotional involvement/sadness, to be specific. We aren't talking about sadness in the "Why did I rent Popeye with Robin Williams, that was awful" sense, either So, which one is it that you can't help but be moved by during the "sad parts"?
I must admit, mine still is Toy Story 2. Exquisitely made and fun film that just happens to have one of the most heart-breaking and sad sequences ever made, in my opinion. I don't quite tear up over it or anything, but it is sort of "chilling" and effective this can be in terms of emotional involvement on part of the audience:
Go ahead, watch this anew and don't feel some tugging of the heartstrings, I dare you
[ame=http://www.youtube.com/watch?v=px0j1EHF8Y0]YouTube - Toy Story 2: When Somebody Loved Me.[/ame]