I've now seen the first episodes of Shingeki no Kyojin and Aku no Hana. Gargantia's supposed to be streamed tomorrow.
Aku no Hana aired with... well, a bit of a shitstorm. It heavily uses rotoscoping (an animation method where something is filmed normally, then that footage is traced by the animators) and has an... unconventional artstyle (notably, it's a show about Japanese high-schoolers drawn to look like actual Japanese high-schoolers). It got panned in most places and it'll probably be one of the least-favored shows of the season.
Because people are idiots. Aku no Hana's artstyle and animation are brilliant. It's dark and ugly and horrifying and unnerving and absolutely perfect. It's art. I don't know if it's going to be any fun to watch, and it's really unsettling, and a lot of people are going to hate it. Those things are precisely what make it great; it's creepy and offputting and beautiful and overwhelmingly detailed and not quite real, and by using such a style, it approximates a visual equivalent to Les Fleurs du Mal (the book of poetry that plays a major(?) role in the plot)'s style.
I'm pretty much gushing, but it's really one of the most remarkable things to come out of the anime field in... years. Maybe ever. It could stand right up there with "actual art". It kinda reminds me of Haruki Murakami, really.
Shingeki no Kyojin... It's pretty awesome and a very solid adaptation of very good source material, but it really feels kinda... empty, after Flowers of Evil. But it's still an excellent show, at least going by a really strong first episode, and probably the one I'd most recommend this season.