1. Genesis- The Lamb Lies Down on Broadway. A very confusing, disturbing and mysterious story drives what is - in my opinion - Genesis' best album. Part of what makes it so excellent is how, upon starting to understand the story, you want to discover what the hidden moral meaning behind it is. As many have said before me, perhaps there is no definite meaning, and it must be left up to individual interperation.
2. Pink Floyd - The Wall. Bitter social commentary that may seem rather disjointed at first, and also straying far from the usual Floyd album, but nevertheless a masterpeice.