Most interesting shows:
Haikyuu S2 - The second season of the well-produced and engaging volleyball series. It's a conventional sports story, but the strong focus on a team dynamic, which lets each character have a unique place in the ensemble and brings clashing personalities together into effective teamwork, makes it stand out.
Lupin III: Italian Series - It's notable whenever this storied franchise gets a new entry that has more effort put into it than the usual yearly TV specials, and the return to the light-hearted adventure atmosphere that Lupin is traditionally known for should make this more successful than the experimentation gone awry that was the Fujiko Mine TV series. The production looks pleasing, with colorful, vibrant art, and we know an Osamu Kobayashi solo episode is part of the series, which is always an event. Hopefully this can capture the spirit of what made Lupin at its height (Caligostro) so appealing.
Noragami Aragato (S2) - The first season was a big surprise to me, treating this shounen action story with an uncommon amount of thoughtfulness in its visual and aural direction and moments of atmosphere that approached the heights of shows such as Flowers of Evil and Hyouka. I'm especially looking forward to the new season because it will be adapting the Bishamon arc, which is considered by manga readers to be a strong highlight and will be focusing on an interesting character who went underutilized in the first season. Plus more Taku Iwasaki goodness.
Osomatsu-san - This is the show I'm most looking forward to from the fall season. It's a new spin on an old comedy manga from the 1960s, with a strong staff including Youichi Fujita, who proved his comedic directing skills on Gintama, Naoyuki Asano, one of the strongest active character designers with a distinctive voice, and Seiji Tamura, who contributes strikingly beautiful backgrounds to the productions he provides art direction for (including the K-ON series, the Fujiko Mine TV series, and Rolling Girls earlier this year). The visual style looks unique and arresting, and there's a lot of potential boiling here.
Other possibilities:
Concrete Revolutio - The visuals are really colorful and polished, if a bit garish, and the melting pot of superheroes premise has potential. The Seiji Mizushima/Shou Aikawa combination is iffy though - their work on the original Full Metal Alchemist series was excellent but their more recent outings have been less successful.
Fushigi na Somera-chan - I haven't watched Ai Mai Mi, but it is fairly well-regarded so this new series from the same manga author and anime creator is worthy of note. Itsuki Imazaki has brought a level of visual flair which rises above the crowd in all the short anime he's worked on recently.
Garo: Guren no Tsuki - The first Garo anime season was inconsistent, but had some striking highlights. The Heian period setting and female protagonist are noteworthy aspects of this new season.
Kagewani - I haven't seen Yami Shibai, but that horror short series has good impressions so this new "monster suspense" series from the same creator is worth consideration.
Mobile Suit Gundam: Iron-Blooded Orphans - Gundam is a franchise littered with mediocrity and Mari Okada's brand of melodrama is problematic at the best of times, but Nagai is a skilled director so... you never know? At least it won't be senile Tomino?
One Punch Man - The manga has such incredible art thanks to Murata that it'll be practically impossible for the anime to live up to it, but Shingo Natsume and a team of high-class animators working on the adaptation make it about as promising as it could be. Hopefully the show will be able to capture some of what makes the manga so beloved.
Sakurako-san no Ashimoto ni wa Shitai ga Umatteiru - This adaptation of the light novel "A Corpse is Buried Under Sakurako's Feet" catches my eye mostly due to its premise - a high school student teams up with a beautiful woman in her twenties to investigate various incidents surrounding bones. It could prove to be a more grounded and substantial story than is typical for light novels.
Shin Atashin'chi - Not much is known about this new incarnation of the well-known family comedy, but if experienced comedy director Akitaro Daichi returns to the series it could be successful.
Subete ga F ni Naru - This adaptation of a serial murder mystery novel by the author of Sky Crawlers, featuring character designs by respected manga artist Inio Asano (Solanin, Punpun) has some potential.
Young Black Jack - A spinoff of Osamu Tezuka's classic series about the titular unlicensed genius doctor. There's no way this will live up to the classic OVA treatment of Black Jack by Dezaki but it could prove entertaining in its own right.