Änglagård are absolutely incredible! Hybris and Epilog are both incredibly great albums, which, I think, might appeal to many Opeth fans who are not hesitant to go into a much softer kind of music: just like Opeth, both of those albums have a great mixture of progressiveness, innovation, and atmosphere. Epilog is probably my favourite album from the two, as it strays further from any prog rock-cliches that might still have been apparent on Hybris, and seems overall the more atmospheric album of the two.
Still, I only have these two albums as mp3 on my computer, because I have never seen any place (not even online vendors)selling Änglagård albums... except for the live album, which I am a bit hesitant to get first, because the only track I heard from that was clearly not as good as the studio version. I'll try some of the suggestions given on this page, though.
Never checked out Anekdoten, though... I guess I'll do, some day, when I'm in a progrock-mood again...
And, now we're talking about prog rock bands anyway, how about Camel? I know they have been highly influential on Opeth, so there might as well be some Camel fans in here... I have heard the albums Mirage, The Snow Goose, Moonmadness, and Stationary Traveller, and can only say that I like all of them... Even Stationary Traveller, which seems to have quite a few influences of 80s synth pop, still retains the beauty, melody and atmosphere that make me like the other Camel albums I heard, so much.