Let me help.
Keane - A Bad Dream (one of the saddest songs you will ever hear)
Something Corporate - Konstantine
Beck - Lost Cause
Joshua Radin - Winter
Damien Rice - 9 Crimes
Cold - Bleed
Dream Theater - Wither
Jeff Buckley/John Cale - Hallelujah (either version works)
Muse - Exogenesis: Symphony Part 3 (Redemption)
Coldplay - What If
I could think of many others, but those were the ones that came to mind first.