I have listened to a fair amount of post-rock, as I often like to read while listening to music, and find post-rock fits the bill for that.
I have found that a lot of post-rock music is pretty mediocre and gives a bad name to the post-rock genre itself. In some cases the musicianship is weak (Yndi Halda) and in other cases the music is just very predictable and boring (Laura, This Will Destroy You).
I used to listen to Godspeed quite a bit and think Lift Yr. Skinny Fists is a classic, although the recording quality is poor and their compositions are admittedly epic in length. But "Gathering Storm", the first cut on that album, is a masterpiece.
"The Earth Is Not A Cold Dead Place" by Explosions in the Sky was in heavy rotation for a while. I think it is a great album for its exquisite melodicism. But their other albums pale in comparison.
The post-rock bands that I have kept coming back to over the years are: Sigur Ros, Do Make Say Think, Mogwai, Mono, and Boards of Canada.