Hmm.... Never Too Late by either Simple Plan or Three Day's Grace. I forgot which band sug/played that song but it's really good. :)
As for a hopeful song, I'm going to suggest a somewhat dark but yet romantic song: Whiskey Lullaby by Brad Paisely and allison kraus or Life Ain't Always Beautiful by Gary Allan.
Another romantic song would be Somewhere Out There, though I forgot who sang it. V.V
Demolition Lovers. Oh man; I could name a million my My Chemical Romance that are dark and romantic. Just look up some of My Chemical Romance's old songs. You'll find a ton.
Christina perry? Herrm. Aerosmith. Maybe o_____o uhhh evanesence hah. Hmm I like this song it's more of a love song kinda.. As much as I ever could - City and Colour. It's not a very popular band, hah it's just one guy actually. BUT YEAHH.