First Daniel Johnston song I ever heard was "Rock n Roll/EGA" in Empire Records. I loved that song the second I heard it, but it wasn't till about a year ago that I bothered to look through the credits and find out who it was by. After that it was just a few song downloads before I was a fan.
I have the live versions from SXSW and David Bowie Meltdown 2002, and neither of them are the version from the trialer. I want to get that version, it's totally sweet.