Village Bridge for sure. It's a bridge, made into a town, it is so pretty, and the music is adorable. <3 Plus in B2W2 you get to beat a snarky, arrogant old man, so that's always fun.
Not only that but it's just a lot more fun to be there, with so much to do. In BW they have a little mini sandwich shop where you can serve people sandwiches at everyday, patches of grass with neat Pokemon in them, trainers, and plus, when you talk to some of the people, other instruments and sounds are added to the music (this is true for both of the games).