Thought I'd revive this thread by posting some of my favourite post-2000 black metal songs. This isn't a definitive list or anything, but perhaps other posters can share some of their favourites.
Averse Sefira - Helix in Audience
Intelligently crafted while being absolutely vicious in its execution. This song showcases everything that's great about their brand of complex, dissonant black metal. 5:20 - 6:55 is absolutely mesmerising.
Deathspell Omega - Carnal Malefactor
DsO really go for the jugular here in terms of trying to provoke a deeply emotional response and it works. Fucking sublime and their crowning achievement.
Hail - Let the Wolves Lead You to Satan's Glory
Often described as the bastard child of Varathron and Beherit, this is drenched in absolute filth and evil. Can't get enough of that scream at 8:25 and the ensuing riff.
Mgla - Presence 1
This does absolutely nothing new, but successfully channels the second wave with such passion and conviction that I don't care. Highly memorable in the way it develops and the vocals are wretched in the best way possible. 5:12 - end is intense, heart-pounding shit.
Sorcier des Glaces - To the Snow Crowned Mountains
Like Mgla, SdG manage to emulate their influences without sounding derivative and boring. Pure frozen majesty and incredibly passionate in their delivery. This is one of the few newer black metal records I've attached nostalgic feelings to.
Griffar - A Host in the Toad Candle
I'll forever be a slave to this kind of hypnotically melodic with heavy blasting kind of black metal.
Belenos - Tal ifern
Intensely passionate and bursting with a prideful energy, Belenos were at the top of their game here. Slower, emotional passages are punctuated with violent explosions of epic tremolo blast riffs.
Negative Plane - Intro/The Chaos Before the Light
Highly unique, Negative Plane blend a wide range of influences yet somehow manage to create something so coherent. Absolutely fucking deranged and strangely morbid. It's hard to describe exactly what they sound like, but for me this is like the sound of a corrupt, demented religious cult committing unspeakable horrors in some kind of despicable cathedral.
Nokturnal Mortum - The Voice of Steel
Surprisingly inspired for a band's 6th full length release. I can't think of many other songs that convey this much pride in their country and heritage.
Wolfnacht - Ein dämonischer Winter verhüllt den Schattenturm...
Utterly detached and alien sounding but also incredibly transporting. It is easy to get lost in the textures of this.
Missing loads of course, but these come to mind right now. Share some of your favourites!