Superman by Taylor Swift?:)

Just so You Know jessi Mccartney
and for the 6th book, when thye are together and they break up and harry sees her in the seventh book and doesnt know what to do, You're Beautiful James Blunt
and when harry starts crushing on Ginny in Book six and doesnt know how to go on about it , Crush by David Archuletta.
Mine by Taylor Swift
thats about all the ones i can think of right now :D

Ivisable - Taylor Swift
Hey Stephen - Taylor Swift
Breathless - Taylor Swift (After Battle of Hogwarts)
Beautiful Eyes - Taylor Swift
You Belong with Me - Taylor Swift
Super Man - Taylor Swift

I would absolutely recommend "Rhythm of Love" by the Plain White T's. Possibly "Just the Way You Are" by Bruno Mars.

i would reccomend Ryth of love by Plain White T's,
You belong with me by Taylor Swift
Crawing back to you by Backsteet Boys