I don't know that I'd agree that Disney is the best that North America has to offer in animation, they are are one of our high end studios...but that leaves out Iron Giant, Prince of Egypt, Cats Don't Dance, Ice Age 2 (which has just made $80.2 million in it's opening weekend), Corpse Bride (absolutely hilarious stuff going on the background - this film was better than I expected), Wallace & Gromit.
Disney does some of the best American based animation, but they aren't the only ones.......
Also, I've noticed a lot of people talking about realism is Disney animation and tho' it has qualities of reality...when was the last time you saw a talking Mermaid with really big eyes? Dogs, cats or other random animals that talk? (Which also have highly exageratted eyes) A Beast that lives in a castle? (Well, I suppose this could be argued in other parts of the world.)
The one thing that both Anime and Disney have in common is that, believe it or not, they both deal in fantasy. Disney fans see Disney animation as realistic, but it actually is just as unreal as Anime due to the fact that it revolves in a fantasy world. The animators that I admire most do their hardest to make the motion believeable, make it
human like but if you look outside of the all encompassing Disney towards actually more-realistic animation you'll find yourself caught up in a world of cartoons that have strong social messages.
I've seen a short cartoon that deals with a Jamaican (sp?) womans life after her husband is killed by drug dealers. She wonders what will happen to her daughter now and herself. The drug kingpin fellow brings them to him. They don't live in nice castles or houses or spaceships or futurisitic environments...they live in the ghetto and it's not very pretty. Her house is in disrepair, her clothes are not the best and it deals with a very strong "drug-use" storyline. It was a powerful piece and I remember sitting there when it was over just staring at my computer screen...thinking "Wow". I myself really dislike politically based cartoons and in general, cartoons with a message - but this one and 3 others I've seen just blow me away. They are so much more realistic that it's scary when you watch them.
Note: I do love Disney animation with my whole heart and they are tops in my book as well, but please don't exclude other quality animation because it isn't Disney.....there's a whole other world out there....you should check it out......you won't be dissapointed (most of the time).