Recommend four out of this list...

Practice What You Preach is a good album, but don't get it unless you already have The Legacy, The New Order, and The Gathering, as they're all better.

Fuck, I think "Souls of Black" is golden. It's their best album. I like "The Ritual" a lot too. "The Gathering" isn't as good as any of their first five albums IMO.

I can't help you with what you should get because I haven't heard everything there, but I know I need to get more Deathspell Omega, so I would get those myself. Ulver also sounds interesting.

Only thing I would steer clear of is 1.3.8. not because it sucks, but because there is potentially better stuff on your list.
 
Except Devourment got the third highest number of votes, which means I was going to buy it regardless of your opinion.

Oh yeah, lol at The Gathering being one of Testament's best albums. Low and Demonic are infinitely better.
 
Actually, I jest, as I HOPE you know. But truthfully, I am not familiar with most of that stuff. I have Beyond the Crimson Horizon, but am not familiar enough to recommend it (except based on the general consensus among those who are familiar). I am not even sure if it was Nightfall or Tales of Creation that I used to have, but whatever it was ruled, and it's hard to go wrong with classic Candlemass. Flotsam and Jetsam - Doomsday is an all time favorite for me. I never liked anything else they did, but Doomsday effin rules!