Jongup's is G.Love & Special Sauces' 'Milk And Cereal'

Yongguk's is Michael Jackson's 'We Are The World'

Himchan's is (lol) RuPaul's Cover Girl 

I think Youngjae's could be the chorus part of Move . Just that part lol

Daehyun's is 2Ne1's I Am The Best.

Zelo's is Adam Sandler's Seven Foot Man.

:)