Lets see here...
I have ZERO death metal albums, and I think thats because I've been looking in the wrong places.
The only jazz album I own is
Cosmos by Sun Ra, and it's not even on a format that I can listen to (its vinyl, and I lack a turntable).
The Only Post-rock Album I own is
Lift your skinny fists... by GY!BL, and I love it, so I want to look more into that.
The only Post-Hardcore album I own is
Relationship of Command by ATD-I, which is now one of my favorite albums.
Some accessible routes for these genres would be greatly appreciated.