Kill La Kill and Non Non Biyori are the most posted-about shows, with Kyoukai no Kanata and Blue Steel Arpeggio not far behind. (There is a higher than usual number of negative posts in the Kyoukai threads.)
Log Horizon and White Album 2 (an odd couple) are the next group, followed by Nagi no Asukara and Strike the Blood.
At the other end of the scale are Yozakura Quartet, Diamond no Ace, and Gingitsune. The latter two are among my own favorites, lol.
Here is the full list, showing number of thousand-post threads:
|Kill la Kill||35|
|Non Non Biyori||33|
|Kyoukai no Kanata||29|
|Blue Steel Arpeggio||24|
|White Album 2||18|
|Nagi no Asukara||16|
|Strike the Blood||16|
|Sekai de Ichiban Tsuyoku||9|
|Diamond no Ace||6|
If I've missed a show or two, please let me know. I know the list is missing popular shows such as Valvrave and MonogatariSS, but the threads for those shows continue from previous seasons, so I can't identify threads specifically for the current season.