for me all snsd ballad song is the best..
the latest is lost in love and promise..mistake and how great is ur love also okay..if u one others group..try 2am..they are awesome..

Lost in love by TaeNy.
I won't love by Baek Jiyoung.
I do not know if this one can be consider a balad, but My Bell by Kim Jungah is so beautiful.

U can try urban zakapa.. They r my fav

Pretty much the whole Secret Garden OST is magic and perfect :)

2am!!! :):):)

To me, SNSD's ballad are one of the better ones.
Like dear mom, star star star, forever, how great is your love etc etc.
TTS's love sick and baby steps!
2bic - 24hours later
Taeyeon's OST - if, i love you, closer.
Tiffany's OST - Because its you, im alone

Haha, a lil biased because of snsd!