I absolutely agree with nearly any song with violins in the background/added to the song.
Most of the obvious choices have been recommended so I'll recommend two songs. One is firmly pop/rock, the other not so much.
Hurricane. This is by Theory of a Deadman - who are largely a mainstream sell-out Nickelback wanna-be... this song is fucking amazing though. The violins are off and on the whole way through song - but make sure you catch the opening/intro and the solo/bridge at around 2:30.
Owner of a Lonely Heart Violin Cover. Probably one of the best pop covers I've seen period. The fact that he does it so well with violin ensures this will remain in my favourites folder for as long as I can use the Internet.