What minor songs from anime do you think are underrated?

I was thinking of two songs I've met through anime that are really special to me, namely, "...To You" by Ayako Kawasumi, the opening from the small anime "Piano: The Melody of a Young Girl's Heart"; and "Never Looking Back" by Shizukunome, the second ending to You-Gi-Oh!! SEVENS.

So, what are some small pieces you'd like to highlight?