In my personal opinion Highschool dxd needs a season 4, one punch man,blue exorcist and attack on titan ALL need a season 2
Blue exorcist has got a season 2!! Yaya and one punch definitely needs one!!! :D and aot is coming out this year!!!! ^^
Haruhi Suzumiya since the series/movie only go through book 5 or so.
Also, Black Lagoon, and most of all, Aku no Hana (the anime only goes through volume 4 of the manga, so not even half the story).
basically all Madhouse anime.
tokyo ghoul is getting a third season
read the manga
Amagi brilliant park!
Crys inside as I realised they will never make a season two :(
^ light i will find you i warn you :P
nichijou is top list for needing a new season