Are Opeth a death metal band?

for some reason I always called them a "swedish mysterious pine tree progressive dark death with some fuzzy classic guitar parts-metal"

..duuh..
 
No. . . there is noticeable growth from each Opeth album, but it is subtle. Each album has its own sound. They just don't make drastic leaps in style changes like other prog bands do, because I think Akerfeldt writes and plays the kind of music he wants, rather than worrying about being more progressive.. Probably the most drastic would be the change in their sound from Ghost Reveries to Watershed.

you dont think still life to black water park is a big change more than ghost reveries to watershed?
 
I don't know. It may have been a bigger change. I'd have to listen to Still Life one day and throw in Blackwater Park the next, but just thinking about the two albums you may very well be correct.
 
heh I saw cephalic carnage a while back at this place in Corona, CA that got shut down called The Showcase, and all the bands just blazed and drank beer in the back parking lot since no one cared, and I started talking to them about music and metal bands and stuff and brought up Opeth and the drummer John was like "you know, I wrote that band off as deemo, (emo death metal, i presume? lol), but after hearing Deliverance I became a fanboy real quick."
 
BIG change between SL and BWP. And another big change between My Arms and SL. You are right toast. Then Damnation comes in with a big curve ball.

I think "curve ball" is a perfect description of Damnation, rather than a change in sound, since they have always incorporated acoustic and mellow segments into their songs. Akerfeldt actually planned Damnation and Deliverance to be a double album, but scrapped the idea.
 
While overclassifying bands can get pretty silly I truly feel that having genres and sub genres if only to be used as descriptors (rather than an actual mold a band has to perfectly fill) can be useful, especially for new listeners. There's a huge amount of music out there and it can get pretty overwhelming finding new music to suit your tastes, especially once you delve beyond the top 5% household/mtv/radio names.

So rather than saying Opeth IS a DM band, or IS a prog band. "Opeth is a metal band with elements of prog and death who explore both the heavy and light sides of music" totally beats <insert genre>

It's really a matter of perspective of looking at genres as descriptors rather than... "genres"