"I Turn My Camera On" - Spoon (on episode "Cheatty Cheatty Bang Bang" of Veronica Mars)
"What Can I Say" - Brandi Carlile (on episode "Enough is Enough" of Grey's Anatomy)
"Just Another Girl" - Pete Yorn (on episode "Credit Where Credit's Due" and pilot of Veronica Mars)
"Breathe Me" - Sia (on episode "Everyone's Waiting" of Six Feet Under)
"We Used to Be Friends" - the Dandy Warhols (on some episode from Season 1 of the OC and the theme song of Veronica Mars)
*EDIT: And one more for good measure: "I Fought the Angels" - the Delgados (on episode "Deny, Deny, Deny" of Grey's Anatomy)
**EDIT: All the links should be working again. I switched my file-hosting site, so the mp3s are actually high-quality now too!