Holy crap, this song has always reminded me of the Weasleys and there's actually a video to it! :D
I was introduced to this song by this video and now it's become a Snape anthem for me.
This one stays because I found the song through this video and now it is the permanent soundtrack to this chapter for me.
The Trio - Little Wonders
Harry himself - Anything But Ordinary
Hermione Granger's theme song
Ron Weasley's theme song
Ginny - Stone Cold Sober by Paloma Faith (skip to 0:37 for the beginning of the video)
Luna Lovegood's theme song
Neville Longbottom's theme song
Dumbledore - Little Lion Man by Mumford and Sons