I have a whole bunch of songs that remind me of The Host. My playlist is:
Run - Snow Patrol [Ian/Wanderer]
"Even if you cannot hear my voice, I'll be right beside you dear."
Say When - The Fray [Wanderer/Melanie/Jared/Ian]
"Two ghosts in one mirror."
You - The Pretty Reckless [Wanderer/Jared]
"You don't want want me no, you don't need me. Like I want you, like I need you."
The Only Exception - Paramore [Kyle/Sunny]
"Darling, you are the only exception."
When You're Gone - Avril Lavigne [Melanie/Jared]
"When you're gone, the peices of my heart are missing you."