Hmmm, I don't think I'm alone here but my idea of "heaviness" was always a song that sort of disorienting at least the first few times you hear it. You know, something like Immolation on their 'Close to a World Below' album, or 'Obscura' by Gorguts. Meshuggah is waaay up there too .
But I'd also go as far as saying that the really dark ambient stuff is 'heavy' in a similar way. Stuff like Lustmord... anyone else now what I'm talking about?
Sepultura's Refust/Resist FTW. This song just has energy, energy and more energy - and then adds energy and turns up the volume. Plus, those samba drums at the beginning just fuckin' slay.
Very good choices, all, although some of the songs you guys mentioned I have not heard before.
My votes would have to go along one of two reasonings:
1) Heaviness per minute: "You Suffer" : Napalm Death, because the song is heavy all the way through the entire 0.2 seconds of the song, so 100% heavy divided by 1/300 of a minute equals 30 000 heavy points.
2) As far as a song that is heavy and enjoyable, with enough variation in it to keep things interesting, I'd go with "Smasher/Devourer" : Fear Factory. I'm not a huge FF fan, although I enjoyed much of Dino's work with them. The song just seems to smash and devour.
Honorable Mention: Chains of Humanity : God Forbid 43% Burnt : Dillinger Escape Plan Domination : Symphony X Lament of a Mortal Soul : Arch Enemy Painkiller : Judas Priest A Very Intense Battle : Estradasphere (or Burnt Corpse ? from same album)
Profitable Killcount - Beneath the Massacre has the heaviest breakdown Ten Ton Hammer - Machine Head Cast down the Heretic - Nile saw and carnage - Aborted is prestty fuckin heavy Lie to my face - Carnifex is pretty fuckin mad, especially that low "ffaaaaaccccceeee"
my votes go to: Cannibal Corpse - Infinite Misery (no vocals in this song to F*** up the groove)
The Tony Danza Tapdance Extravaganza - The Electric Boogaloo (downtuned seven strings doing dive bombs on the low string)
Suicide Silence - Destruction of a Statue ("ok heres my idea for a song: lets make a super crushing heavy riff , then at the end of the song, we'll 1/4 time that shit .. ahh yeeeaah!")
Weird , i just realized that all the songs i mentioned play in a Ab tuning of some kind....whoa , trippy.