I too would have to go with Tokyo Hotel MiraCosta. The detail inside and out is amazing and the fact that they got this hotel to blend in flawlessy inside of the TDS park is also a crowning achievement in itself.
I would love to see Walt Disney World built their own 5-star resort with the class and detail of MiraCosta. I bet you the Disney nuts would pay good money to stay in a room like that.
Second runner up goes to Animal Kingdom Lodge. I've always wanted Disney to do an African-lodge theme hotel.