[IIL] Dark animation like The Hobbit (1977), Princess Mononoke, Secret of NIMH, Nightmare Before Xmas [WEWIL?]

I've always been really into dark, creepy animated films like those listed above. I've seen most other popular animated films in this category (Coraline, All of Tim Burton, most of the Studio Ghibli films, etc.) I'm looking for less well known suggestions, or other media I might enjoy with a similar style.