Top 10 Best Extreme Metal Genres
Extreme metal is a term for a number of related heavy metal subgenres that have developed since the early 1980s. This list includes extreme metal subgenres and fusions between same extreme metal subgenres or between other genres.
Death has to be the most extreme. I've never heard a Thrash Metal song about ripping entrails out of a virgin or a song about ripping flesh off of someone's body and wearing it as a mask. Even Slayer and Kreator don't sing about stuff like Cannibal Corpse, Six Feet Under, or Morbid Angel. So Death is the most extreme!
So much diversity within its subgenres and the amount of experimentation. This is what defines extreme metal as well as the complex song structures and intricate riff patterns.
Death is the definitely the heaviest genre, Please explain why Thrash is number 1? There is no ways that thrash can be heavier than death metal.
Thrash is only extreme to teenage girls and dad rock fans. Death metal is the most creative and most technically demanding musical genre.

Why is there a guy who seems to think symphonic black metal is heavier than black metal and makes lists with made up genres such as "Nu extreme metal"? Anyway, black metal is the most "extreme" genre in my opinion because not is only the music is very inaccessible, but the violence and Satanism that occurred during the second wave hasn't really been seen in any other metal genre.
Death, Black, Death-Doom, and Funeral Doom are pretty much the only metal sub-genres I find myself gravitating to the most. I don't dislike other sub-genres, but they no longer captivate me as much as they did during the initial phase. Once you immerse yourself into or embrace extreme metal, the lust for dark music only intensifies after each listens.
When it comes to 'trve'ly extreme metal subgenres, you can never talk about it without mentioning black metal.
Some say death metal is more extreme, but just to make sure, no death metal(or any other metal) bands never burnt down a church, never murdered a person, and never took a photo of a former band member who killed himself.
This is a list of EXTREME METAL genres, not a list of anything that can make you think you're badass. Bands like Dimmu Borgir, Marduk or Behemoth are really extreme metal bands. For Doom, Thrash and Grind, I am ok but NO for all that is under Metalcore on the list! Black Metal is extreme because it's evil, Death Metal because it's heavy. Here is my list :
1 Symphonic Black Metal
2 Death Metal
3 Black Metal
4 Thrash Metal (true thrash bands, not like Metallica)
5 Metalcore
6 Goregrind
7 Black death
8 Nu extreme metal (bands such as Slipknot)
9 Doom
10 Gothic Metal

Thrash metal, doom metal, death metal, melodic death metal, black metal and grindcore are the only genres that should even be here. Stuff like power metal, groove metal and metalcore don't belong on this list because they aren't "extreme" metal genres. The fact that nu-"metal" is here is laughable.
Thrash is most extreme and it sound heaviest and just Thrash! Thrash Metal was push to all other extreme subgenres of metal. Genres like Death, Black and Groove Metal, and also Grindcore and Deathcore. Thrash is extreme life
Musically thrash metal is the most exstreme genre. Shrieks or growls doesn't make the music more extreme by any means and neither does satanism/violence in the lyrics. Even if satanism/violence made it more extreme some thrash bands clearly trumps other genres
May not be the heaviest, but it is the fastest and most aggressive. Has renowned scenes all over the world ranging from Brazil, Europe, the American East Coast, and the legendary Bay Area.

This is where we reach the end of music. This is the most noisy genre that can still be considered music before you start entering real noise territory. I'm not sure why this isn't #1 though. It combines the extremes of goregrind and harsh noise, and offers loud guitars, fast drums, and outrageous vocals.
Grindcore might not have the most disgusting lyrics, such as stuff, listed in the death metal description. Yeah, of course, some bands like AnalC*nt can go far and sing about pornogring or gorerind, I forgot, but I'm talking bout those bands, who actually formed grindcore as a genre. For example, my favorite band Napalm Death. They are the fathers of grind and no one can deny that, but if you take a look at lyrics, or try to actually listen to em, you wont hear them singing about a woman, whose eye got poked out, and then someone with aids, no-no-no. They are singing about politics and about not bring treated fairly. The true heaviness comes with the music. Listen to their first album, "Scum" its called. Only the drums will make your ears bleed badly within the first minute of any song, lets say "Instinct of Survival". If you listen to their last album, "apex predator - easy meat", maan, not only your ears will bleed, but your teeth will brake and your brain will run away. After all, ...more
Grindcore is simply the end of all things extreme, the intensely downtuned guitars and blasting drums there's nothing that tops grindcore, not even death metal. For any confirmation listen to Brutal Truth - Birth of Ignorance. Grindcore is a wall of brutality and it's brilliant.
Grindcore is among the most progressive and harsh musical styles of all time for me. Its unsympathetic, abrasive songwriting style and harsh, brutal instrumentation puts it up at the top of my list.

Very abiguous genre. There are so many different types of Melodic Death.. While I love bands like Insomnium, Be'Lakor, Carcass, At The Gates, Persefone, Quo Vadis, Intestine Baalism etc., there are also many many bands I dislike, who are considered as one of the best and genre-leading ones.
But still. I enjoy the gems of this genre, and I guess that's all that counts in the end.
How can anyone not love bands like Insomnium, Arch Enemy, Noumena, and Wolfchant?
Veil Of Mya all the way on this one. Mikasa and Doublespeak. Good stuff.

Easily the heaviest genre. People like fast metal, but there's nothing like the MASSIVE sound of Doom. It's the closest "modern" genre to bands like Black Sabbath. How can that be a bad thing? I love faster metal like thrash and death metal, but there's nothing quite like the sheer heaviness of doom. It gives you this "trudging through mud and sludge" kind of feel. Music is about feel, not super technicality (that doesn't hurt though), and Doom definitely has a very unforgettable feel to it. It's like being crushed with a massive wall of sound, and I love it.
Doom metal, the genre that has the slludgiest, fattest, most overwhelming sound. Speed vs slow have different types of heaviness, but slow has an overall more overwhelming sound, thereby being the heaviest. The heaviest music I have heard before has been doom metal. One time I listened to Son O))) in the dark in the middle of the night, and I had to turn it off because it was just so heavy and intense. I've listened to Slayer and Canibal Corpse in that same situation, and I could get right through, because it was heavy, but not THAT heavy. I'm working on music for an indie game my friend is making, and I wrote a couple doom metal riffs for it, and he had to turn it off for the intensity. He never did that with thrash, death metal, or prog riffs. Just more evidence to show that doom is truly the heaviest genre.
What other genre could exceed the huge sound that dominates your ears that doom/sludge/stoner/drone metal does? Fast playing guitar is fantastic in its own right, but it just doesn't bring the same balls that this genre does.
Love doom. Should be above thrash at least, but I still think black and death metal deserve to be above doom metal even if I prefer doom metal myself.

It's brutal and unforgiving to both the listener and performer. Whether or not you like it, I would argue that it is heaviest by the fact that it can incorporate all the intensity of death and mix in the rebellion that hardcore punk was founded on.
The dynamic of going really fast to really slow and sludgy makes deathcore feel more intense than death metal, that's just my opinion and feeling of course.
This should be the number one heaviest genre of metal. It has everything that Death has + breakdowns, chugging and more blast beats
All you people who think Metallica (E-Standard Tuning and Clean Vocals) are heavier then a band like Infant Annihilator (Drop F Tuning and no clean vocals) or Rings of Saturn actually need to realize this is 2015 not 1980.
Blackened Death Metal has got some of the heaviest drumming ever.
Drummers like Inferno of Behemoth and Marthyn of Belphegor take it to the next level.
Behemoth are awesome!
BEHEMOTH! At the left hand ov god is my second fave song after hammer smashed face

Off of topic if Progressive/Technical... Technical Death and their branches is one of the most important variations in the last decade in metal, the techsdeath musicians have skills beyond than the thrashers, the aggressiveness are equally to any black, and the fussion/progressive songwirting it's at the same level of other bands dedicated to his genre; it's not a war about definition it's about recognize one of the genres must underrated/polemic in Metal! this goes from Obscura to Quo Vadis, from Origin to Nile even Gojira licks this genre. Thrash Forever! but Techdeaths are in my heart!
Too many people here think Technical Death Metal and Progressive Death Metal are the same, but it's not. They just overlap very often.
While bands like Horrendous, Cynic or late-era Death (e.g. The Sound Of Perseverance) are very progressive, they aren't really technical.
On the other hand bands like Nile or Suffocation sound very technical, but not so progressive.
Of course many bands fit into both categories: Obscura, Beyond Creation, Lykathea Aflame, Gorod.. just to mention some.
I believe Technical Death Metal is the best and most extreme metal genre, especially its more brutal versions, and should be at #1. Bands - Nile, Cryptopsy, Brain Drill, Necrophagist, Obscura, Gorguts, Fleshgod Apocalypse, to name a few.
The techdeath is an evolution, without doubt Thrash is the best but if you really want hear virtuous musicians this is the genre, agressivenes... this is the genre, even if you really want to learn to play an instrument see what this guys do, amazing!
How in the WORLD is brutal death metal not at #1.. bands like maggot colony and analepsy make all the other subgenres of metal sound like kids bop...
Brutal Death and its subgenres are superior to any other of genre period.
Brutal Death Metal is strictly heavier than Death Metal hense the name. How is Death Metal #1 and this 11?
Why is this not in top 10?
Well if you think last days of humanity and regurgitate are less heavy then cannibal corpse and nile then you are correct. but In reality goregrind while yes can be slow and grindy at times bands like carcass, regurgitate, last days of humanity, rompeprop, etc are in fact much more heavier, but technicality wise death metal is heavier, but if gore grind is below power metal in heavieness this list is wrong. just listen to reek of putrefaction by carcass or putrefaction in progress by last days of humanity for proof that goregrind is in fact much more heavier (not more technical)

It's not my favorite subgenre, nor do I believe metalcore should be #1. However, due to the fusion of screaming or growling vocals and brutal breakdowns, I stand by that you can find a lot of songs that are heavier than a significant amount of thrash metal songs.
Listen to the album "Caliban - Vent" and you will understand why Metalcore is heavier than Black metal and Thrash!
Metalcore is a good genre. It actually has melodies and can be artistically creative. Haters gonna hate, it's good if you're openminded and aren't a bandwagoner which is what metal should be all about anyways.
I know a lot of people hate Metalcore, personally I love it, but for the people who don't:
Try the band Northlane. They are awesome.
Genres like Sludge, Death - Doom, Grindcore, and Tech Death can be extreme at times, but the genres most consistently falling into very extreme music are Funeral Doom, Slam Death, DSBM, and Goregrind in my opinion.
The heaviest and slower genre of metal ever. Pounding drums and distorted bass with brutal growling vocals and depressive melodies make this the most lifeless genre on earth! Mournful Congregation, Tyranny, Thergothon, and Bell Witch are some of the best bands in this genre.
A real underground genre, emerged in the early 90's in Finland. Similar to Death/doom.
Painfully slow, heavily distorted guitars, majestic keyboatrds and extreme deep growls.
Check out bands like Skepticism, Esoteric and Worship.
From a fan of everything extreme from powerviolence to grindcore to slam to blackened death, I can honestly say this is the heaviest genre. Slower than hell, but in a way such as a steam roller would destroy a body. Dark, resonating and extreme to the core. Try rigor sardonicous, mournful congregation, thergothon and evoken.
Svartsot is some really heavy viking metal. Mixes death with folk instruments and viking themes

My favorite genre. The old Katatonia, My Dying Bride. It fuses the beauty and emotion of doom with death's raw anger which complement each other perfectly.
This is the fusion genre of Death Metal and Doom Metal.
Autopsy changed my mind about Death/Doom, amazing.
I like speed metal very much but it's not extreme. Speed metal is just a faster, heavier and more technical version of power metal - some songs by Blind Guardian (Majesty), Helloween (Ride the Sky), and similar.
Some people used to call bands like Iron Maiden and Judas Priest speed metal in 70s and 80s.

It's not extreme - there's nothing extreme here. Not fast and not aggressive. And vocals are clean.
Amazing, bands like Silencer are the creepiest thing I've ever heard. It should get more votes.
Hands down the best

It is not a good for listening but in terms of heavy, it is epic.
This subgenre of grindcore is plain insane. Disgusting stuff
I know this genre is worthless but we are talking extreme genre not the best. So this deserves the no.10 spot. Grindcore, Blackmetal, Deathmetal,e.T. C might be in the greatest chance of being number 1 but it deserves top 10 spot.