Team Yume
While waiting (waiting, waiting...) for the new Mogwai album to turn up on Emusic, I've started to look into other ambient-melodic-instrumental rock-pop.
The best I've found so far is Yume Bitsu ("Dream Beats" in Japanese, apparently). They're a little darker than Sigur Ros, a little brighter than Mogwai, and they make spacey, alone-in-the-dark music.
In particular, I'm really enjoying the 18-minute epic "The Frigid, Frigid, Frigid Body of Dr. T. J. Eckleberg" on their self-titled album, which is a glorious wash of chiming and distorted guitars, atmospheric feedback and ghostly vocals. (Here's the album on Emusic. If you're not a member, they offer a free trial that let's you download 50 mp3s.)
In case you're wondering, Dr. T. J. Eckleberg is from The Great Gatsby:
Doctor T. J. Eckleberg: This is a billboard advertisement depicting a huge pair of bespectacled eyes staring out across the ash heap. Wilson later points to this saying, 'God sees everything' before going on his murderous rampage. (Via Bookrags.)

