Thergothon sounds pretty cool from what I gather... a little raw, but sometimes that works better! I'll have to see if I can't find out a bit more about them. Thanks guys. SOD sound a little too pretentious for me... but I guess that's what I should expect given the name of the music's genre. Lol.
Anyway - I'm a long time Opeth fan... well as long as probably most of you on here... lol! Started following them right before MAYH came out. A few years back Michael used to run the website himself, he posted about 20 different recommendations for bands/albums he considers gems. Most are pretty obscure, some of them are really great from what I have collected... almost none of them are metal music per say... I wish I would have wrote down the complete list. I really forget most of what was on it... IF ANYONE HAPPENS TO HAVE THIS LIST AND CAN EMAIL IT TO ME... I"D BE ETERNALLY GRATEFUL!!
Here's some other interesting atmospheric music I sometimes listen to... a bit different than the bands you have listed here... but if your an Opeth fan, you guys are probably open to most music.
God Speed for You Black Emperor - pretty unique 9 piece chamber/rock band... Not metal at all... and sometimes it's downright boring... however songs start off really slow and then just explode with energy, I recommend everyone at least give them a listen, may or not be your cup of tea... every once it works for me.
Mike Oldfield - Tubular Bells - A true classic... 2 songs. Most of of you probably know this from the movie, "The Exorcist". Pretty great considering this guy plays every instrument on the recording... it's layered like no other recording I have ever heard.
He was only 19 when he did this. On a good stereo, this is really a nice piece to own.
Anglagard - they produced two albums "Hybris" and "Epilog"... and a live recording as well... try to find the two albums, might be hard to find!... pretty great musicians, think dark, progressive, jazz, rock... I think Micheal recommended this one on his web page... can't remember. Regardless, this is pretty good stuff.
Univers Zero - 70's band. Classical music... really dark atmosphere... not rock or metal... these guys were ahead of their time... impressive musicians... word of caution: not for everyone.
But if you can appreciate talent... check them out.