Some of the very good action anime series i've watched
Kill la Kill -
Full Metal Alchemist Brotherhood
Nurarihyon no Mago
Code Geass
Btooom!
Mahouka Koukou no Rettousei
HunterxHunter old or 2011 version
Blue Exorcist
Gurren Lagann
Akame ga Kill
Hajime no Ippo
Grappler Baki
Samurai Champloo
Noragami
Hellsing
Kuroko no Basket
Blood Lad
Cowboy Bebop
Fate series
Hitman Reborn
Darker Than Black
Soul Eater
Yuyu Hakusho
Flame of Recca
Deadman Wonderland
Accel World
Log Horizon
Overlord (ongoing)