Explosions In The Sky: The Earth Is Not A Cold Dead Place (2003)
I can't say I'm entirely clear on the whole "post-rock" genre, which seems (depending on whom you ask) to encapsulate pretty much anything that is either instrumental music and/or experimental rock-adjacent music that eschews traditional verse-chorus-verse structures.
Whatever. I don't listen to a lot of instrumental music apart from Brian Eno's ambient works, but I've developed a real love for Explosions in the Sky, who do a fascinating job of blending ambient music with more chaotic post-punk guitar jams. I particularly like The Earth..., which to my ears sounds like the most melodic excerpts of extended Sonic Youth guitar freak-outs wedged into prettier sonic vignettes. The extended suites somehow manage to be both soothing and cathartic at once, the sort of things that start out perfect for vegging out on the couch or working at home during a pandemic but intermittently transition into frenzied spin-around-the-room discordance, which I'm guessing is a whole lot tougher to pull off than it looks.
Here's a live performance of "First Breath After Coma":