- Covered Up: While not exactly the case, Mikael tends to name songs and albums after obscure progressive rock and metal bands of the seventies. Who honestly remembers bands named Blackwater Park, Still Life, Master's Apprentices, or Heir Apparent?
- Though the original is still far more well known, there's more than one person who is unaware that "Would?" was originally by Alice in Chains.
- While it isn't a cover, anyone who has listened to Camel's "Never Let Go", can tell that "Benighted" uses many elements from that song. This isn't surprising, as Mikael cites Camel as a huge musical influence on him.
- Crowning Moment of Funny: Mikael during this little speech.
- Crowning Music of Awesome: While many fans dispute on which songs deserve the title, it is unanimously agreed by all fans that the epic title track of the epic Blackwater Park album deserves it. "Bleak", from the same album, is also considered an example by most fans.
- "Black Rose Immortal" off of Morningrise is a fan fave, most likely because you must be a true fan to make it through the song's ridiculous length.
- Of course, there's also those who take Ghost Reveries, Still Life, or My Arms, Your Hearse as their most epic album (when it's not Blackwater Park). Hence songs like "Demon of the Fall" or "Ghost of Perdition" get a lot of love too.
- Epileptic Trees: Many speculate that Mikael Akerfeldt is one of the nameless ghouls in the Swedish hard rock band Ghost (known in North America as Ghost B.C.). Some feel that he downright gave it away with the band's cover of "I'm a Marionette" by ABBA, as he's a huge fan of them (and has been known to wear their shirts during Opeth concerts).
- Fan Dumb: Has come out in full force after the release of Heritage and still had not let up by 2014. Many fans spend a lot of time whining about how Heritage wasn't a "real" Opeth album and that the band name should be changed.
- Magnum Opus: Generally considered to be Blackwater Park, to the point where the band has been known to perform the entire album live.
- Mondegreen: There are lots of them, possibly due to the constant use of the Metal Scream. "Deadly badgers made my wreath" (and variations, such as "Deadly badgers rape my dreams") in "The Drapery Falls", "Fresh made tacos of the earth" in "The Baying of the Hounds", etc.
- Narm: The awkwardly quick acoustic passage followed by the even more awkward drum solo at about 8:45 in "To Bid You Farewell", otherwise a massive Tear Jerker.
- Nightmare Fuel : The disturbing face appearing on Watershed's artwork. It is composed from pictures of the band's members.
- Tear Jerker:
- The closing track "Isolation Years", from Ghost Reveries.
- "Hope Leaves", along with most of Damnation.
- "Black Rose Immortal" after around 9:40 and excluding the Last Note Nightmare
- From the same album, "To Bid You Farewell"
- And pretty much every other Surprisingly Gentle Song.
- The acoustic sections in "Dirge For November."
- A heavier example: the aptly titled "Bleak."
- They Changed It, Now It Sucks: Many people had this reaction to Heritage. Gloriously inverted, however, with Damnation.