There are three albums that I just happened upon during the 90's that weren't from giant rockstars or heavily promoted singles, but continue to rank in my all-time favorites (namely, the CD rack where I keep all my current favorite albums for quick listening). Maybe not "the best" of their day, but definitely unsung:
Kyuss--Blues for the Red Sun: A solid album from the force that eventually went on to become Queens of the Stone Age, this album is so thick and heavy, the sludgiest grunge I've ever heard, but also beautiful. The opening track "Thumb" just builds and builds. Other stand outs include "Thong Song" (uh, not that Thong Song) "Allen Wrench" and "Freedom Run." For fans of the Queens, or anyone who was into STP, Nirvana, or Pearl jam in the mid 90s.
Compulsion--Comforter: Another album along the grungier side, and I think the only album this band ever released. It sort of bridges the gap between pure grunge and the new-punk of Green Day. What impresses most is the heart, thought and feeling behind these songs. Great tracks include "Delivery", "Eating", "Mall Monarchy", and "Domestique." Anyone who can straddle punk and grunge will appreciate the sounds here.
Life, Sex, and Death--The Silent Majority: This album is impossible to peg. The vocals are indescribable--from fluttering falsetto to raging bile in a split second. The band comes in as super-processed as any 80's hair band. The songs range from straight-ahead hard rock to bluesy to inspirational. Anothewr band the world never heard from again. Instantly memorable tunes include "Tank," "School's for Fools", and "The Farm Song." I'd say fans of Faith No More or anyone who can listen to both Nirvana and Poison in the same day.