I own "Deliverance" and "Damnation," what should I get next?
Morningrise is probably their most critically acclaimed piece of work. If you took a vote from every Opeth fan on Earth, it'd most likely come out on top. Personally, I enjoy
Still Life the most, just because it really has some of their best acoustic compliments. Not to say their best acoustic work, but the best acoustic work that compliments the metal side of it.
Blackwater Park (my first Opeth album admittedly) is also great at this, but maybe not to the same extent.
MAYH has a really interesting theme running through it (they all seem to be concept albums in one form or another). Each song is kind of forshadowed before the next. It's also got some really catchy stuff and it's a little strange to hear yourself humming the songs, heh. I'd say that the album as a whole flows together better than the rest.
Orchid is quality as well, but I haven't listened to it in awhile.
Fuck, you know what? If you enjoyed
Deliverance/Damnation just buy them all. Heh, seriously though, I'd probably recommend
Blackwater Park or
Still Life to you. Probably just because they're pretty close to some of the stuff in
Deliverance in terms of how it feels to your ear. The lineups prior to that were different as well. The three albums released prior to
Still Life, were a little hard to find (got the remastered version with the ... odd demo tracks at the end), but I think you can find them if you look hard enough.
For reference, the albums go chronologically as follows.
Orchid
Morningrise
My Arms, Your Hearse
Still Life
Blackwater Park
Deliverance
Damnation
Anyway, I would probably consider
Deliverance and
Damnation to be their weakest. I still love them, and I think it was excellent to see how the idea of doing two polar opposite records (highlighting the band's extremes') would work out. Both albums stand alone as being great, but while it's not really fair to critique the albums for missing their opposite parts, as their clear intent was to be written and produced
without those opposite parts, they do sometimes lack some of the progression that Opeth is known for.
I don't want anyone who reads this to get the idea that I didn't like the albums. If you were to put both albums together, you'd probably get another standard Opeth album ... which wouldn't be a bad thing, but a change every now and then is always good.