I'm personally a sucker for Jason Reitman's films, and Juno and Up In The Air had really fucking good soundtracks. Sure, most of the songs are licensed, but the way they are used are perfect.
Genova - Charles Atlas
Help Yourself - Sad Brad Smith
All I Want Is You - Barry Louis Polisar
The Wrestler is easily one of my favorite movies of all time, and the song that Bruce Springsteen wrote for it was just so damn good that whenever I hear it, I still choke up a little bit.
The Wrestler - Bruce Springsteen
Up is fucking awesome, and so is this song. 'Nuff said.
Married Life - Michael Giacchino
This song from Battlestar Galactica not only is fucking great as a song period, but it actually is a huge part of the plot in the later seasons. One of my personal favorites.
Kara Remembers - Bear McCreary
Anyway, that's what I can think of at the moment. Show me what you guys got.