James: 'Helpless' - fight me

Remus: 'Hurricane' - he's been through a bunch

Sirius: 'The Story of Tonight' - he surrounds himself with his friends

Peter: 'The Reynolds's Pamphlet' - I don't know, it just seems like him

Lily: 'Schuyler Sisters' - the energy of the sound just resonates with my idea of Lily

Bonus -
McGonnagal: 'Meet me Inside' or 'Right Hand Man' - no-nonsense authority figure as a parental figure