Art of Animation and Pop Century are the best, though you may want to go with Pop Century. AofA is mainly family suites, and there are very few of the Little Mermaid rooms, which are the size that you would be looking for. If you stay at Pop Century, you are more likely to get a deal on the room, such as the free QS dining plan or a percentage off the room. AofA does have nicer pools and is definitely more "Disney" overall, so if you're willing to shell out a little extra for it, go for it, but if money is an issue, you'd be better off with Pop. What you could do is book a room at the hotel of your choice, then as it gets closer, watch for the deals and jump on the deal as soon as you see it (just call Disney and have them switch you over).
I would not do any of the All Stars, especially if you plan on taking the buses. Pop and AofA are newer, so they're nicer, and they each have their own buses, whereas All Stars tend to share buses, and with two little ones, you'll need good bus service unless you have a car. I stayed at Pop last year, and as I looked over at the mass of people at the All Star bus stops, thought how glad I was that I was at Pop and not an All Star.
I didn't know the all stars were separate buses from Pop Century, so that makes it even better! When does the Mickey's halloween run?
