So... question, floydie - is your list in any particular order?
Sorta.
Top tier:Basically has MAYH as the #5 slot. It's a gorgeous album but I bought it impulsively when Barnes and Noble didn't have BWP and I wore the grooves out on that fucker until I could afford BWP and all the while it was just the Splenda tiding me over when I was pining for a diabetic dosage of some BWP shoogah. In time MAYH has gotten even better than it initially was but I guess I prematurely made it "old" to my ears before it could be seen as anything more than a poor man's BWP to my heart.
The other 4 albums in this tier can change not only by the day but even by the hour for me since I'm so thoroughly in love with them.
BWP will likely never be any worse than tied for #1 as far as my Opeth rankings go. Although Demon of the Fall was the first Opeth song I ever heard, and I loved it instantly, it was Bleak and TLA and Harvest that really won the war early on for Opeth becoming my favorite band since early '04.
Orchid and Morningrise are absolute gems imo and have a fragile wintery beauty to both of them that makes them stand out in the Opeth discography far more than any of their other works. They're so different in the way they have such epic buildups and how Mike's screams are so blood-curdling and emphasized to great effect with the heavy reverb.
I understand why folks generally don't like these two all that much on first listen because I didn't either. I used to just listen to them as full albums while playing San Andreas or some other game I could get lost in for a few hours and eventually I'd hear a riff or section I really liked...then another...and yet another until the walls came crashing down and I wondered why I ever had any reservations in the first place.
Still Life was actually the last Opeth album I got into theoretically since I got into it in mid '06 and the last two albums had yet to come out. After some cheech and chong recreation, songs like The Moor, Godhead's Lament, Moonlapse Vertigo, and Face of Melinda were instant successes. In very little time, this album passed up Deliverance and Ghost Reveries. Damnation was bottom of the barrel for me at this time anyway.
Middle tier:Deliverance has never crawled out of the lower ranks for me. It just has an uninvitingly cold and sterile vibe to it compared to the way that other efforts manage to have a tenderness and comforting nuance to their mayhem. The songs are fun to play on guitar and lack nothing in the area of kicking ass but something just seems missing. I do adore AFJ though and BtPISIO has an intro and verse 1-2 punch that I find to be the finest in Opeth's entire discography in terms of being unique and awesome. Certain things like the droning repetition of parts of Wreath and Master's Apprentices as well as the 4-minute outro of Deliverance really tank it for me and FAF is beautiful yet tedious at the same time.
Damnation is a very close second for worst first impression I've ever had with an Opeth album behind Heritage. It's grown very nicely in time though which is why I put it ahead of Deliverance in that post.
Ghost Reveries is my fave of the middle tier but it has my least fave Opeth track in Atonement (although I have to commend Marrow of the Earth for it's impressive effort to win that crown.) That track really destroys the album's flow for me and I think Hours of Wealth would tie BtM to R/HF a whole lot better. I basically see GR as a very good album that gets weighed down by Atonement, R/HF's overly-long/boring outro, and the over-simplicity of an otherwise good track, TGC. HoW is phenomenal though as is R/HF up until about the halfway part of the outro,
Bottom tier:Watershed was basically just one and a half songs to me for the first few months I owned it, TLE and half credit to HA. HA soon reached full-quality status to me as did Burden and PH. Coil has reached a point where I like it for what it is, a quasi-ballad marking a definitive shift from being a band that's death-metal-first to one finding its way in this previously unexplored arena of prog metal that leans heavily toward prog rather than being a death metal band with folk and prog tinges. As an Opeth song, however, I still find Coil to be a little lacking. Hessian Peel is quite pretty and the heavy second half tickles my scrote gleefully but I just have never looked forward to listening to it since it just seems a bit awkward overall and I still can't properly articulate why I feel that way. Hex Omega is just boredom incarnate for me and I really hope that changes one day.
As for Heritage, I despised it thoroughly when I first got it but it's warmed up enough to where it's passed Watershed for #9. I still like The Lotus Eater and Heir Apparent way more than anything on it but Watershed's weaker tracks make it fall short of the more consistent Heritage. Famine's heaviness and woodwindcore, Folklore's energetic outro, and the many off-kilter yet beautiful melodies strewn throughout the remainder of the album have helped it really crawl out the shitter for me.