For me, it'd be ARIA the Animation/Natural
Aria is a nice calm series. It doesn't rely on action to interest people, nor does it rely on suspense. It's cute, without being a lolitafest. It's characters are likeable all the way from Akari, to the manager of the San Marco square cafe. The sense of discovery and wonder is great and some moments just "wow" me.
Aria is a really laid back anime, and that sets it apart. Sure, I love hyper random stuff, and can't get enoguh of a good deep story, but Aria is the kind of series I can always come back to and know I'm in for a good time, with sweet characters, and a sense of wonder that few other series have.











