Discovering classic albums.

I've been listening to a lot of older albums (usually 20 years or older) on Rido recently, and I've discovered a good amount of awesome classic albums that I couldn't believe it took me so long to discover. The most recent being The Cranberries' debut album Everybody Else Is Doing It, So Why Can't We?. Every song is just amazing. What are some classic albums that took you a long time to discover, but ended up being some of your favorites?