All right, before I say anything I shall say this, I love Pixar, and I love this movie. The atmosphere is great, the story is better than most cartoons, and it has lovable characters.
There is only one thing that bugs me though. The relationship between John and Mary seems so forced. I'm saying it doesn't belong, but either there should have been more interaction between them and it should have been expressed better. It seems slightly out of place, but if there was more character added and more involvement other than the really forced parts (referring to the "Get ready to have some kids" line).
Lots of people love this movie and I can see why, but that whole relationship between those two keeps me from saying I could watch it over and over.
overall, I give it an 7/10 from Pixar standards, and an 8/10 in general movie standards