Morningrise got me into the band, and I loved that album for the longest time with Black Rose Immortal being my #1 fave song for a seriously long time. From there, BWP became my fave. Afterward, MAYH was the album I got into, then Still Life - which actually took me the longest to actually get into.
Now, though...I've been listening to Opeth for a VERY long time, and I can honestly say that, without hesitation....
My Arms, Your Hearse is my favourite release by them...definitely! They seriously got to do another album closer to that style - the more balck metal style. This album is the heaviest one and has some of the most emotional guitar harmonies - it rules!