The first thing that came to mind was "And in the end, the love you take is equal to the love you make." The Beatles - "The End"
"Sometimes I lose sight of where i'm going
Fanned by a flame I can't remember
But distant lights still burn bright
And the road goes on forever"
Fates Warning - "The Road Goes on Forever"
It's not quite the ending lyric, but the last verse of Metallica's "Damage, Inc." is pretty cool:
"Fuck it all and fucking no regrets
Never happy ending on these dark sets
All's fair for Damage Inc., you see
Step a little closer if you please"
"Forever more, into the night, blistering" - Dream Theater - "Constant Motion"
"Spread before you is your soul
So forever hold the dreams within our hearts
Through nature's inflexible grace
I'm learning to live"
Dream Theater - "Learning to Live"