Let's just get this out of the way: I cried like a little girl at the end of WALL-E, not because of the ending, but because of the ending that almost was. I'll get to that in a moment.I think the last animated film I've seen in the theater was South Park: Bigger, Longer & Uncut, back in 1998. (Coincidentally, I also cried during the first 15 minutes of that film -- laughing.) I do not have any recollection of seeing another animated film in the theater beyond that. Ever. Maybe it is because there weren't a lot of animated films made in the 70's, when I was a child, and certainly since I don't have any children I haven't been forced to watch them since. This is not to say that I haven't seen the occasional animated film, but frankly the subject matter of adult-oriented films is usually (an exception: The Incredibles, which I love) preferable to the plots of animated features.
WALL-E is a smart, perhaps too smart, film, as dystopian an animated movie as I've seen. Entertaining from start-to-finish, on the old grading scale, I'd give it a B+ or an A-. It's got so many clever references, that it would be madness to try and list them all. To suffice, you benefit largely from having seen a lot of film. Or, to quote a friend, "Any movie that can pay homage to both the Love Boat and 2001: A Space Odyssey in the same breath is rock solid." But it could have been so, so much more, if for one thing.
Now this is to do about the ending, and if you haven't seen the movie, the following paragraph contains SPOILERS. I woudn't say that they will ruin the movie for you (they are hinted at in several reviews I read), but you have been warned.
I cried for my usual existential reasons. It really hit me out of the blue, when EVE reconstructed a shattered and broken WALL-E with his own spare parts, when he lit up and was back to being an automaton. At that moment, the notion that WALL-E's reward or price for saving mankind would be to lose his personality (or, really, his SOUL) was mind-blowing to me, and way more tragic than that Atonement shite.
However, I KNEW they would bring him back in the end to have a "happy ending", because this IS a "kids flick" and that would be way too much for children to handle. That moment, when WALL-E wakes up some minutes later (due to the hand-holding), was actually anti-climactic for me. I was disappointed. It was being shown a glimpse of something so beautifully tragic and then having it yanked away. Those few minutes in the film, I was streaming tears. And when I think of just that moment, my heart feels a little heavier.
I should point out that the happy ending doesn't ruin the movie at all. If they did leave him stipped of himself, though, I'd say it was an absolute ballsy, stunning end. As it was, still B+.