Well, I personally really enjoyed Fractale. Apart from how gorgeously drawn it was (and one amazing OP), I thought it was great social commentary on organised religion, technology's (sometimes) clash with our humanity, and the use of violence to meet a political end.
And speaking of endings, while it did leave some questions unanswered, I thought the notion hinted at - that the different characters in Fractale existed in the mind of a young girl, and were a reflection of the different aspects and people of her life - was a great Lynchian touch that underlined how much the issues the show addressed effect us all.
There were a few loose ends that could've been tied up, but you know, I've never actually required a story to explain everything to me for me to enjoy it. Overall, I consider Fractale one of my favorites.