Hi,
I wanted to reply as I too was very surprised by how moving I found these two animated films (Waltz with Bashir and Persepolis; I haven't seen Wall-E). Waltz with Bashir in particular was amazing. I found it very beautiful how sharply the portraits were drawn, in just a few strokes -- to pick one at random, the scene where the hero is talking to his friend the shrink, and there is a child in the background throwing a large ball with both hands. I later learned that almost everyone was drawn from life, and indeed there is a trueness to life in the choice of just the right detail, a bit of stubble or a line of tiredness. I was surprised at the maturity and expressiveness of these very simple drawings.
Perhaps for this reason I wasn't thrilled with the ending. I liked the truth of the world which he had drawn and found myself immediately distrustful of "other" images. Of course, I can see why it was an important move.
Persepolis was wonderful but entirely different. The animation, coming as it does from a graphic novel, is much closer to the sorts of old cartoons we saw as kids, which are abstractions rather than portraits, and really give the feeling of a storyteller recounting a story (which was indeed the case). It's a life story in history, which even though it leads up to the present moment, provokes the kind of melancholy which comes from understanding complicated issues in the past and seeing someone's history. But it's less a commentary on the present moment. On the other hand the feeling of Waltz, which I'm sure was helped by the use of color and detail as well as the subject matter, was that of understanding something basic about the present -- I don't mean politically necessarily, but emotionally.
Also, especially in the case of Waltz with Bashir, I thought the soundtrack was extremely well done.