I really liked Kohei Tanaka's orchestral music for Gaist Crusher. It's nice to see he actually got a budget for it. He composed the OP too!
Shiro Hamaguchi wrote some orchestral music for Galilei Donna too. There was definitely some good stuff, the main theme definitely stood out. Will need to hear more though.
Speaking of main themes, I quite liked Hikaru Nanase's choral main theme for Kyokai no Kanata. The rest of the score was alright but nothing amazing.
Tokyo Ravens had some good piano/strings music in episode 1 with a hint of greater things to come. Surprised this is by Maiko Iuchi. I'm convinced someone else is arranging her compositions because it doesn't really sound like her style based on what I've heard. Especially considering the was an orchestral track at the end of the episode and she isn't an orchestrator as far as I know.
EDIT: Keiji Inai's
IMAGINE profile has been updated and now lists arrangement for Tokyo Ravens. Hayato Matsuo and Yasunori Iwasaki might still be involved even though their pages don't mention it (the
Index movie, for example, isn't listed despite their involvement).
By the way, I checked out Nagi no Asukara today and noticed there were five additional people credited for music in the end credits. Yoshiaki Dewa is the main composer but Zentaro Watanabe, Saigenji, DEPAPEPE (Tokuoka Yoshinari & Miura Takuya) and Shunsuke Kawata are also contributing. Interesting is that these guys are all acoustic artists. DEPAPEPE is actually a pretty well known acoustic guitar duo.
Oh and also, it hasn't been announced, but I have learned that MOKA☆ will be doing the music for the horror anime Pupa which airs some time this season. That should complete the fall 2013 list unless I'm forgetting something.