This Google search should help you. (In case you get didn't get the cool "Music albums frequently mentioned on the web" scroller that I got, it mentions Godspeed You! Black Emperor in the first spot, followed by Sigur Rós, Explosions in the Sky, Mogwai, and others) In addition to that I'll add Broken Social Scene (not post-rock, but fellow Canadians, and great music, check out the album You Forgot It In People), ...And You Will Know Us by the Trail of Dead (more post-hardcore than post-rock, but Source Tags & Codes is a fantastic album) and Deerhoof (way more out there, not for everybody, but Apple O' is a classic if you give it a chance) Cheers, and enjoy your adventure!
Definitely Mogwai, that's precisely what I thought of coming into this thread. Explosions In The Sky is absolutely phenomenal, I personally love Your Hand in Mine although that entire Album The Earth Is Not a Cold Dead Place is really good. The first track First Breath After Coma is so emotional and I adore it. Also there's a version of Your Hand in Mine with strings which I really love too. I've had a few conversations with friends about what we felt when we listened to that track. I really feel with the original version that it's more of a war march. Does And So I Watch You From Afar count? I feel like they do. Just had a thought. God Is An Astronaut Try them as well!