Most Artistic/Progressive/Experimental Albums You Own

Venetian Snare's 'Nymphomatriarch' was composed from samples of Aaron having vaginal, anal and oral sex with his girlfriend of the time (Hecate, who the record was made with) and also the sounds of arse spanking.

Pretty darn cool album too.

I'd love to hear how Funk managed to get his girlfriend to agree to let him record them having sex.

"So honey, I'm making a new album and...."
 
Most expérimental:
- unexpecT - In a Flesh Aquarium
- Age of Silence - Acceleration
- Akphaezya - Anthology II
- Carnival in Coal - French Cancan/Fear not
- Peccatum - Lost in Reveries
- Sleepytime Gorilla Museum - Grand Opening and Closing

(All of these are approximetly egual in experiamental-ship)

Most progressive:
- Pain of Salvation - Enthropia
- Ayreon - Into the Electric Castle

Most Artistic ("beautifull"):
- Akphaezya - Anthology II
- The Gathering - Home


The best mix of all these qualities: To-Mera - Delusions

did you know that some bands (only the really experimental ones) have actually tried making music that's not metal? i'm not sure how it worked out but it's an interesting idea
 
A few off the top of my head...

JAZZ:

Miles Davis - Bitches Brew

Surrender to the Air - S/T


So- Called "Classical" (Chamber Music, etc):

Frank Zappa - The Yellow Shark

Arnold Schoenberg - Pierrot Lunaire, Moses und Aron, etc. etc.

Anton Webern - Everything

Alban Berg - Wozzeck

ROCK:

Amon Duul 2 - Yeti
 
to add to my previous list, I totally forgot about Circulus! An excellent psych-prog-rock band. Definitely and acquired taste though.
 
I read the whole thread and I'm amazed that no-one has mentioned:

Captain Beefheart & His Magic Band - Trout Mask Replica

The Jesus and Mary Chain - Psychocandy
 
Everything I have has already been mentioned except everything by pan.thy.monium.