anime according to JLPT level (= N5 is easiest, N1 is hardest). at animelon.com you can watch anime with japanese subs connected to a pop-up dictionary; other recommendations are viki (= j-dramas+subs), japanese netflix (= japanese dub+sub).

• example: you're at JLPT N3 but want to beat N2. watch Kabaneri, Parasyte, Shiki etc THEN jump a difficulty line and watch Baccano, Hunter x Hunter. to really ensure that you'll pass, jump another line to Death Note, Psycho Pass and so on.
• after 60-80 episodes (with no outside study) you should be able to jump a level.
• ♫ means there's background noise or music that makes it hard to hear.

updated: 2018.02.08

Animelon:
1. (N4-N3 level): Black★Rock Shooter, Chobits, Chuunibyou demo Koi ga Shitai! Ren, Flying Witch, Kobato, Shingetsutan Tsukihime, Ping Pong the Animation
2. Angel Beats, Full Metal Alchemist: Brotherhood, Furusato Saisei, Gekkan Shoujo Nozaki-kun, Nyan Koi!, ReLife, Slam Dunk, ♫Tokyo Ghoul
3. (N3-N2): Kabaneri of the Iron Fortress, Kuroko no Basuke, Parasyte, Re:Zero kara Hajimeru Isekai, Shiki
4. Baccano, Hunter x Hunter, To Aru Kagaku no Railgun S
5. (N1): Death Note, Fate Zero, Psycho Pass, ♫Attack on Titans
6. JoJo's Bizarre Adventure, Shinsekai Yori

Elsewhere:
1. (N4-N3) Devilman (70's TV series), Kobayashi's Dragon Maid, Pokemon (Season 1-2), 1st Pokemon Movie
2. Devilman Crybaby, In Another World With My Smartphone, Jyuu Oh Sei, Net-juu no Susume
5. (N1): Death Note, Fate Zero, Psycho Pass, Slayers, The Twelve Kingdoms, ♫Attack on Titans
6. Overlord
J-Dramas on Viki:
(N3) 僕のいた時間

Special Notes:
— Flying Witch: really useful for "everyday Japanese" in case you're going to actually live in Japan. "Pass me the frying pan" "Take the trash out" "Mind the gap between the train and the platform" etc.
— Psycho Pass: almost every sentence uses N1-N2 grammar points with VERY clear context, so if you're studying advanced grammar try this series.