mine would be Switch, One Piece and the live version of Sayonara My Friend... hmmm.. Switch, there's something about it that even i doesn't know. One Piece and Sayonara My Friend, it must be the soothing melody and the awesome lyrics.
I know it is not their song but I love "Secret base", when Haruna starts singing it makes the hair on the back of my neck stand up, and I love how Tomomi gets all excited at the end ! But then I love all their songs.
it's one piece whenever i listen to it my soul feels calm and soothing and i feel like crying and the lyrics too i always listen to this song when im alone coz i find tranquility and i also wanted to cry its been a long time since ive cried