Without hesitation it's ( ). I got the CD around November 2002 and used to let it play over the night until 2004, when it got replaced in my nights by múm (that was probably "Summer make good"). It's been years I haven't played music while sleeping though.

I'm not familiar enough with entire albums, just tracks. But now I'm going to pick up Með suð í eyrum við spilum endalaust as my starting point.

that too is a lovely song, thank you. I enjoy the look of this video as much as the music, so pretty.