Awesome Music: Given that it is their most well known album (and a fan favorite), all of Enthrone Darkness Triumphant qualifies. The music in Death Cult Armageddon is also essential listeningnote It certainly helps that it is one of very few metal albums of the 21st Century to receive a perfect five-star rating from AllMusic. In general, pretty much all of their 'classic hits':
"Mourning Palace"
"Spellbound (By the Devil)"
"In Death's Embrace"
"Master of Disharmony"
"A Succubus in Rapture"
"Kings of the Carnival Creation"
"Progenies of the Great Apocalypse"
"The Serpentine Offering"
"Gateways"
"Dimmu Borgir"
"Puritania"
Broken Base: Widely argued, but the best candidates are Enthrone Darkness Triumphant, Puritanical Euphoric Misanthropia and In Sorte Diaboli.
Nothing even comes close to the division regarding Eonian. It was either worth every second of the wait and is a bold new direction for them, or it's a monumental failure on par with Catharsis, Illud Divinum Insanus, and the Suicide Silence self-titled that is one of the biggest disappointments of the decade.
Ensemble Dark Horse: ICS Vortex and Nick Barker. The former's body of work is widely respected even by those who don't like Dimmu Borgir, while the latter is a highly revered and influential drummer as a whole.
Fan Nickname: Demon Burger, usually by the band's detractors.
Growing the Beard: While the first two albums and the early EP's are well-received (and, indeed, the only things they ever did that the really extreme Black Metal fans like), many of the band's fans agree that they really hit their stride with Enthrone Darkness Triumphant.
Narm: The band's lyrics and overall presentation can come across as this to those not interested in or familiar with Black Metal, and even to the more extreme fans of the genre.
Nightmare Fuel: Tormentor of Christian Souls. The lyrics are not overly graphic, but still extremely disturbing. The narrator gloats about how he could torture and rape someone but won't because instead he wants to break them mentally by destroying everything they love.
Signature Song: "Mourning Palace" or "Spellbound (By the Devil)" for Enthrone Darkness Triumphant, "Progenies of the Great Apocalypse" for the whole band.