So why is it that Pixar are a step above the rest in the animated film world?

I personally believe it's the ideas that the people behind the making of it have. They think outside the box. The films include adult material and child material, which give the films a more underline meaning than some cheap kid cartoon. From the research and feedback i have, it seems to me that people enjoy Pixars comedy and the way in which they present events we see in our everyday life. Another thing i have noticed is the main charcters used in the films are simple creatures and things. I mean, A Rat, A Robot, Toys, Bugs, Cars, Fish! If you described to someone that there was a 2 hour movie about Bugs they would probably avoid it like the Plague, but in Pixars case, they turn it into something amazing! So i ask you, why is it that Pixar are so good at what they do? What makes them THE BEST!?