Mamamoo and Monsta X I know nothing about, but as for the rest:
iKON- After their survivals (in which list I'd include The Remix) I'd recommend their 100 Days Journey docs (the dvd version of WIN); their Season's Greetings dvd, Kony's Summertime dvd, the documentaries in their Showtime in Seoul and Japan dvds, the behind the scenes videos uploaded on their Youtube channel, Mary & I (with Hanbin & Jinhwan), BOBBY's Daddy & I, Sugarman (BOBBY & June did a great collab song there, did you watch it?), Running Man.
EXO-I don't know how long you've been a fan, but the best material imo is in their EXO First and Second Box dvds, behind the scenes on the EXO planets concert dvds, EXO Showtime, EXO XOXO, EXO 90:2014, Surplines EXO, EXO Channel, Running Man, Laws of The Jungle and Roommate.
I must thank Naver for V App, it's so useful for typings