[AutotelicBrown]

1. Usagi Drop

Other 9 in no particular order:
-Ashita no Nadja
-Cardcaptor Sakura
-Revolutionary Girl Utena
-Azumanga Daioh
-Yuyushiki
-Honey and Clover
-Kino's Journey
-Magical Girl Lyrical Nanoha
-Haibane Renmei

Few extras because I'm not good at ranking things:
-Golden Time
-The Melancholy of Haruhi Suzumiya (honorable mention to the movie "The Disappearance of Haruhi Suzumiya" although I'm not ranking movies here)
-Arakawa Under the Bridge
-Serial Experiments Lain
-Excel Saga
-Mushishi
-Maria†Holic
-Darker than Black
-Aria the Animation