One of the most underrated albums, in my opinion, is Tears for Fears' 1995 release Raoul and the Kings of Spain.
This was Roland Orzabal's second release without Curt Smith on bass/vocals. The album is a true masterpiece from top to bottom, that moves like a concept album, though in essence it's more thematic if anything. Every time I give this record a listen I get goosebumps from Roland's powerful and emotive voice. Lyrically speaking, it's dark, the music is moody, the melodies are infectious, and the production is fantastic. It's definitely one of their heaviest records to date, which touches on several topics ranging from family, relationships, and love, to spirituality/religion, etc. I use the term "heavy" not in terms of metal, but from an emotional standpoint.
There is so much more to Tears for Fears than the pop songs that they've become known for that have become staples in every '80s music collection. I'm really looking forward to their new record!