I believe Shiki deserves a place here too. It's a bit like Shin Sekai Yori in how it's originally a book, slow paced at the beginning, and is rather stressful at the end. The lore, world, and themes may not be as developed or interesting as SSY, but it deserves a mention.
Ikuhara's works as well, Penguindrum and Utena are among my favorites, having a unique presentation that makes otherwise bland shows into something spectacular. Surrealism is not for everyone, but it should be given a try.