Toy Story
A simple movie of a child's toy collection coming to life and causing all kinds of fun antics. The first sad thing here is that Woody, a long time favorite of Andy's, was replaced by a newer and cooler toy Buzz Lightyear. Ignore the crazy antics and look at how Woody has to deal with being replaced, sucks right?. Now think about all the toys and how one day Andy will forget about them and they will all be replaced by technology and fine trim. The other toys will either be forgotten in a closet or sold in a garage sale or garbage, either way they are fucked. This tells kids that you can be forgotten to the ones you love.
Monsters Inc.
A group of monsters find new excitement at there boring jobs scaring children. The excitement being a little girl who enters there world and causes crazy antics. This movie gets really sad towards the end when Sully has to give up the only joy that came into his miserable life, not to mention this last act is a tear jerker, for a kids movie they really know how to pour the emotions out. But all is better when years i assume later Sully sees this child again and is happy. This shows that if you hate your life and job something new and exciting will come along, but dont get to attached because it will get taken away from you. Great lesson Pixar.
The Incredibles
A family of superheroes come out of retirement and save the day. The movie starts out depressing when you are introduced to this world where superheroes can no longer save the day, sound familiar? Yeah think "Watchmen". To be honest that is a awesome concept wherever it is. So the father who is super strong gets sick of his boring suburb life and in a series of events comes out of retirement. Another point is the main villain who was once the main heroes biggest fan but he fucked him over, this tells kids "Your heroes will screw you at some point" and isnt that the truth. And finally the funniest scenes are showing past superheroes being killed due to their capes (also in Watchmen). I guess accidental murder is funny to kids.
I wont talk about Finding Nemo because i really didnt care for it
So there you have it...Pixar can do a great kids movie that appeals to all ages.