Studio Ghibli (スタジオ ジブリ)

I'd say Pompoko. There's a heavy environmentalism message throughout, but it's all conveyed to you by Hobbit-like, shape-shifting raccoons with huge nutsacks (in a charming way).

Kiki's Delivery Service, Ponyo, My Neighbor Totoro, Howl's Moving Castle... All of those have at least one scene that rips at my heartstrings. Much more so for Spirited Away, Princess Mononoke, The Boy and The Heron. I still haven't steeled my resolve enough to watch Grave of the Fireflies.