Lol, let's not start this all over again.
Anyway, Opeth's influence are quite varied. As Mike states on his myspace:
"Shit...loads! The Beatles, Black Sabbath, Judas Priest, Led Zeppelin, Kent, Dio, Scorpions, Jan Johansson, Accept, Kiss, Brian Auger, Rainbow, Deep Purple, Billy Cobham, Bo Hansson, Life, The Zombies, Bobak Jons &; Malone, Jackson C Frank, Fläsket brinner, BKO, Circus 2000, Mark Hollis &; Talk talk, Black widow, The Knife (Karin Dreijer Andersson), Bathory, Mars volta, Pink floyd, Metallica, Bobak, Jons &; Malone, Possessed, Pretty things, Camel, Doris Svensson, Rainbow band, Lucifer's friend, Porcupine tree, Morbid Angel, Colosseum, Nucleus, Joni Mitchell, Can, Nick Drake, Culpeper's orchard, Spring, Seal, Museo Rosenbach, Pussy, Queen, Tea party, Jeff Buckley, Budgie, Salamander, COB, Manowar, Scott Walker, David Sylvian, SBB, Celtic Frost, Popol vuh, Focus, Heart, Stina Nordenstam, Skid row, King Crimson, Monica Zetterlund, Master's apprentices, Blue phantom, These trails, Spiritual beggars, Mefisto, The Electric Prunes, Nevermore, Nicholas Greenwood, Message, Solarplexus, McChurch Soundroom, Prof. Wolfff, Emtidi, Eugenspygel, Mecki mark men, Midlake, King Diamond &; Mercyful fate, Clutch, Made in Sweden, Marie Fredriksson (Den ständiga resan), The doors, Ibrahim Tatlises, Gorguts, Chris Cornell, Cressida, Thin lizzy, Gracious, Whitesnake, Comus, Hendrix, Jerry Goldsmith, Stina Nordenstam, José Gonzáles, The Who, ELO, Jeff Beck group, Flower travellin' band, Free, Ark (w/Jorn Lande), East of Eden, Bathory, Jethro tull, Sandy Denny (Fotheringay &; Fairport convention), Danko Jones, Fleetwood mac, Iron maiden, Grand Funk Railroad, Candlemass, Paatos, Linda Perhacs, Europe, Entombed, Van halen, Alice in chains, Fredrik Throdendal &; Meshuggah, Circulus, Uriah heep, Van der graaf generator, Radiohead, Goblin, Three man army, David Axelrod, ELP, Spirit, 30-åriga kriget, Stevie Wonder, Darkthrone, Gentle giant, Alice Cooper, Euroboys, Emperor, Jon Lucien, Tool, David Bowie, Wes Montgomery, Miles Davis, 2066 &; then, Toad, Alice Coltrane, Travis, Death, Affinity, Katatonia, Anekdoten, Morte Macabre, Robin Trower (with James Dewar!!!), 16 horsepower, Air, Captain beyond, Alphonse Mouzon, Carmen...yeah, you get the picture....pretty much everything that's good! As for musicians...Guitars: Ritchie Blackmore, Jerry Donahue, Andy Latimer, Yngwie Malmsteen, Matthias Jabs, Wes Montgomery, Uli Roth, Michael Shenker, Robin Trower, Jimi Hendrix, Al DiMeola. Vocals: David Coverdale, Paul Rogers, James Dewar, David Vincent, Stevie Wonder, Ann Wilson, Joni Mitchell, Paul McCartney, Ronnie James Dio, Rob Halford. Playlist right now: The Zombies - Odessey &; oracle (A true masterpiece!)"