If you’re a fan of grunge history, one album you should listen for is called Deep Six. This is a compilation from late 1985 released on an indie label called C/Z Records. Some people believe that this record kicked off the whole grunge phenomenon.
It features early material by Soundgarden, a band called Skin Yard (which featured Jack Endino, who later produced much of Nirvana’s early stuff), Green River (featuring future members of Pearl Jam and Mudhoney), and the Melvins, the group considered to be Nirvana’s most important influence.
If you want to hear where grunge came from, the CD has been reissued several times.