I'm gonna reccomend a few albums that haven't been mentioned yet, and I consider to be great post-rock releases:
Tortoise-Standards (my favorite by them, TNT being a close second. Check this out NOW, probably my favorite post rock band right now)
Labradford-E Luxo So (Some people don't consider them post rock. I do, and this is my favorite release by them)
Tarentel-From Bone To Satellite (simply awesome)
I'm gonna have to agree with Luminous here and reccomend Agaetys over (). I don't hate () or anything, I just think it's not as good as it could've been.
Hmm, like everyone before me, I'd reccomend GYBE!-Lift your skinny fists... (when the exclamation point was at the end of their name
). Their EP (Slow Riot for New Zero Kanada) is quite good as well.
Oh yeah. you should check out some of tis year's releases as well. My favorites are:
A Silver Mt.Zion Memorial Orchestra and Tra-la-la Band with Choir-This is our Punk Rock...Thee Rusted Satellites Gather + Sing (pretentious band/album name aside, I like this release a lot)
Do Make Say Think-Winter Hymn Country Hymn Secret Hymn
I've seen some elitists around here who instantly label you a moron if you list any post rock band that comes from a well known label, or that doesn't come from the more obscure scenes. These people are complete retards and you shouldn't listen to them, they can masturbate to their ultra rare underground noise bands all they like. Anyway, that list should be more than enough to get you started