I have been wanting to do a post like this for a while. I recently rediscovered the first few Black Sabbath albums and have been playing them mercilessly. I generally concentrate on the heavier stuff as is my wont, but I am endlessly facinated by the softer side of Sabbath.
These few tracks demonstate a nice duality to the Black Sabbath aesthetic. One moment they can be bombastic heavy bastards raging at War or their own weaknesses, and then turn on a dime to do a folky prog number like Planet Caravan.
In my previous incarnation as an ambient DJ I liked to slip one of these in on off moments and then surprise those that asked "Who is this?" with the answer Black Sabbath. It invariably led to a shocked face and hopefully a more open mind.