Who did the art direction on for these episodes and scenes? There's a certain art director whose art I absolutely love. I can name a few episodes and shows I saw his touches in.

Shin Sekai Yori - episode 5 and 10 (dunno if any further).
Kimi no Iru Machi - mostly in the beginning, also opening, fewer scenes in the latter part.
Casshern Sins - many scenes

His works are very distinct and have many traits to it. Among others they're:


Angles. He uses a lot of different angles everywhere. Characters are rarely drawn in straight angle, the camera is looking from either higher or lower point. Sometimes it's also rotated a bit.
He focuses on faces a lot, putting emphasis on the eyes. Faces cover most of the screen whenever a character is talking and there's no other action going on. Also apply angles argument to that.
Some scenes just belong to a certain character, having only him and nothing else apart from the plainish background on the screen.
Emphasis on body movement, especially hands and posture.
Dynamic scenes consist of characters moving from one part to another, rotating from side to side. Sometimes background is still while character is moving on the screen.


What is his name and what other works did he work on?
I think you're looking for Junichi Hayama. He was the animation director for episodes 5 and 10 of Shin Sekai Yori as well as on staff for the other 2 shows you've listed. Some of his other works fall into the same characteristics you listed.

You can see some of his art from a Google image search

Among other works:


Afro Samurai: Resurrection (movie) : Key Animation
Be-Bop-Highschool (OAV) : Character Design, Animation Director
(The) Big O (TV) : Animation Director (ep 21)
Casshern Sins (TV) : Animation Director (eps 10, 17, 22), Key Animation (5 episodes)
A Certain Magical Index (TV) : Key Animation (OP1)
Cobra The Animation: The Psychogun (OAV) : Key Animation (ep 2)
Dokidoki! Precure (TV) : Key Animation (ep 7)
Doraemon: Shin Nobita to Tetsujin Heidan - Habatake Tenshi-tachi (movie) : Key Animation
Dream Eater Merry (TV) : Key Animation (OP; ep 13)
EX-Driver the Movie : Key Animation
Fist of the North Star (movie) : In-Between Animation
Fist of the North Star (TV) : In-Between Animation (4 episodes), Key Animation (3 episodes)
Fist of the North Star 2 (TV) : Animation Director (7 episodes)
From the New World (TV) : Animation Director (eps 5, 10), Key Animation (eps 5, 10)
Fullmetal Alchemist: Brotherhood (TV) : Key Animation
Gaiking: Legend of Daikū-maryū (TV 2/2005) : Illustration
Gu Gu Ganmo (TV) : Animation
Gundam Build Fighters (TV) : Key Animation (OP)
Gunsmith Cats (OAV) : Key Animation
Himitsu no Akko-chan: Umi da! Obake da!! Natsu Matsuri (movie) : Key Animation
(The) IDOLM@STER (TV) : Key Animation (ep 9)
InuYasha the Movie 3: Swords of an Honorable Ruler : Animation Director
JoJo's Bizarre Adventure (OAV) : Storyboard (ep 8), Character Design (eps 1-13), Chief Animation Director (eps 9-13), Animation Director (eps 1-2, 6-8), Cover Art, Key Animation (eps 2, 5-7, 13)
JoJo's Bizarre Adventure: Phantom Blood (movie) : Director, Character Design, Chief Animation Director
Kimi no Iru Machi (TV) : Chief Animation Director, Animation Director (OP), Key Animation (OP; ep 1)
Kyō, Koi o Hajimemasu (OAV) : Character Design, Animation Director
Locke the Superman: Mirror Ring (OAV) : Character Design
Lupin III: Stolen Lupin (special) : Key Animation
Manyū Hiken-chō (TV) : Animation (OP)
Mobile Suit Gundam AGE (TV) : Key Animation (eps 40, 49)
Mobile Suit Gundam UC (OAV) : Key Animation (ep 3)
Mysterious Girlfriend X (TV) : Animation Director (ep 9)
Nessa no Haou Gandalla (TV) : Character Design
New Fist of the North Star (OAV) : Key Animation
Odin - Starlight Mutiny (movie) : In-Between Animation
On the Way to a Smile - Episode Denzel: Final Fantasy VII (OAV) : Animation Director
Pachislo Kizoku Gin (TV) : Character Design
Paranoia Agent (TV) : Animation Director (ep 9 ["TKO"])
Penguindrum (TV) : Key Animation (ep 18)
Pokemon Heroes - Latias &amp; Latios (movie) : Key Animation
Psychic Wars (OAV) : Key Animation
Rurouni Kenshin: Trust &amp; Betrayal (OAV) : Key Animation (ep 1)
Sailor Moon R Movie: Promise of the Rose : Key Animation
Sailor Moon SuperS Movie: Black Dream Hole : Key Animation
Saint Seiya Omega (TV) : Key Animation (ep 51)
Sakigake!! Otoko Juku (TV) : Animation Director (8 episodes)
Shin Kyūseishu Densetsu Hokuto no Ken: Raoh-den Gekitō no Shō (movie) : Key Animation
Shin Kyūseishu Densetsu Hokuto no Ken: Toki-den (OAV) : Character Design, Animation Director
Space Battleship Yamato 2199 (TV) : Key Animation (ep 25)
Star Driver (TV) : Animation Director (eps 9, 18)
Street Fighter Alpha (movie) : Key Animation
Toriko (TV) : Key Animation (OP)
Transformers (U.S. TV) : In-Between Animation
Transformers: Scramble City (OAV) : Key Animation
Votoms Finder (OAV) : Character Design, Animation Director
Wolverine (TV) : Key Animation
(The) World God Only Knows Season Two (TV) : Key Animation (ep 4)
X-Men (TV) : Animation Director (ep 9), Key Animation (OP; ep 12)
Xanadu Dragonslayer Densetsu (OAV) : Key Animation
Yu-Gi-Oh! (TV 2/2000) : Animation Director (eps 94, 124)