FRANCE. My answer will always be France. Heck, I've been to actual France, and my favorite place on Earth is still the France Pavilion! The memories of watching Impressions de France, then coming outside to sit at one of the tables, soak in the sunshine, and eat sorbet and French pastries are some of my favorite memories ever. Then again, I am a huge Francophile, but still, I just think it's such a pretty and happy pavilion.
I also love Japan, Canada, and Germany. Japan because I've always wanted to go there and I think their culture, food, and architecture is awesome. Canada because the actual Canada is arguably my 2nd favorite place outside of Disney (1st is, of course, France), O Canada is such a great show, and I love the replica of Le Château Frontenac (which I've been lucky enough to actually visit!). Germany because I'm German-American, my favorite type of food is German, my favorite meal is schnitzel, and my favorite restaurant in the world is Biergarten. Also, I'm a sucker for the teddy bears
Oh! And Mexico. I looove Mexico.
They're all so great, though!