Hi
Enjoying this thread, I have seen quite a few of these bands and I agree the term is a bit too broad to be helpful. A couple of other bands I've seen to add:
[b]Slint,[/b] who allegedly released the first post-rock labelled album though they're more math-rock maybe. One of my favourite tracks:
[media]http://www.youtube.com/watch?v=b4XJFsAUYFU[/media]
And no one yet mentioned [b]Rothko[/b], who have 2 bass players:
[media]http://www.youtube.com/watch?v=urCW3mEu-ak[/media]