I’m a rank newbie, but here goes..
Folk :
Eva Cassidy is way up there on my list. I’m into folk quite a bit, and Waylin Jennies sometimes.
Rock :
Recently listened to Eric Clapton (Unplugged) - just awesome acoustics.
World :
I’ve been listening to african and world sounds (mostly via putumayo) - "Reggae from around the world", "Maali" are awesome acoustic recordings.
There are some CDs in my collection that scare me, they’re so good I’m scared I don’t have the preparation to sit down and listen.. Example. by a band called Red Tail Ring "Fall Away blues".. its a haunting album (Eva Cassidy used to occupy this pedestal once).
There’s a turkish one with Sufi music.. Its there sitting among my 100 odd CDs I’ve only listened to it once.. Scary good, literally.