Natsume Yuujinchou was a big surprise for me (in the good way). It's not the type of anime I usually look forward, and honestly I don't remember why I started it, but I don't regret it. There is everything, all the human emotion (even if it's trough non-human characters). I cried and smiled a lot, all in simplicity. No big drama, just the simplicity of feelings, the simplicity of life.
It's a anime you can watch at any age, and it just reach you.
And the "plus" of it : you learn about youkai and japonese society in the same time.
I truly recommend those who don't look forward complex stories, but still deep one.