Time for this thread topic to make the rounds again!
Some of my all-time faves:
“They’re popping up everywhere like broke relatives!” - Marin Noggenfogger (during Tanaris Legion invasions)
“So, it has come to this. Together, we have learned and grown over the years, and now we find ourselves face to face on the battlefield. Do not think I will go easy on you, nor do I expect any quarter. What we do now, we do for the Horde, both of us.” - General Nazgrim in SoO
What are some of yours?
“Ha ha ha, such an amusing gesture from the rabble. When I have finished with you, my master’s blade will feast upon your souls.” - Scourgelord Tyrannus
“You DARE look upon the Host of Souls?! I shall devour you WHOOOLLEE!” - Devourer of Souls
“Me Gonna Ook You In the Dooker”
-Ooker Dooker
“Yes, yes, yes…no, no, no no no! Yes! No! Peppers!”
Also pretty much anything from Matron Mother Malevolence because I love her voice acting.
“GOOD NEWS EVERYONE!”
“I think I perfected a plague that will destroy all life on Azeroth!”
-Professor Putricide
I mean even after over a 100 runs in Icecrown that still made me smile everytime I heard it lol
I also enjoy Ka’ro and Grozzaks banter in Dazar for some reason…
By fire be BUUUUUUUUURNED.
… Butt cinders.
I, Gamon, will save us!
Oh good. Here comes xxx; with the Scepter of Sargeras. You know, in case we need to punch a hole in spacetime and shatter the planet.
Tehd
There is so much comedy gold in WoW. It’s what I love about the game that devs don’t take themselves too seriously.
Some favs:
"Don’t look so smug! I know what you’re thinking, but Tempest Keep was merely a set back. " I lol irl every.single.time.
“Well, well! Another group of thieves trying to steal my horse!” Attumen the Huntsmen. Crack up every time.
And last but not least
“The only metric we care about as a development team is whether you’re having fun.” - Watcher the Patient I still want to buy him massive amounts of beer for that quote
YOU ARE NOT PREPARED! 
“Maximillian of Northshire yells: Great Uther’s ghost, it’s chasing after us! Squire, do something! Throw rocks at it! I have no plan!”
Really anything he says and the entire quests from Ungoro to the Paladin Order Hall unlock.
"When I reached the end of the canyon, I remembered that my motorcycle could fly.
That would have been helpful to know earlier".
Hyjal has a couple of my favorites.
Nordu, Ancient of Lore:
It is… too late for me. Burned to all but the core. I have lived eons … yet still my end seems sudden.
New life can spring from old. I still have wisdom to pass on. Please … do not let them take me before my work is done.
Keep the tormentors at bay… just a little longer, <class>.
Give me minutes, and I will give you a thousand lifetimes.
Tortolla:
I slumbered in the healing silt of Hyjal.
I slept until the world broke open.
When the others came, I was not ready.I am ready now, <race>.
My children and I. Slow to anger.
But our wrath is final.Tell those who sent you that we are prepared for war.
The others will be cast from the mountain.
From Archavon’s Log (Wintergrasp):
Day 214760:
The violent little people have started attacking my brothers, which is sad. They leave me mostly alone now though, which is not sad.
I think they want the shiny baubles I gave away. I feel guilty now.
“Prison taught me one very important lesson, well, two if you count how to hold your soap, but yes! SURVIVAL!” - Millhouse Manastorm.
Two quotes both from the Wrathgate cinematic.
“You speak of justice? Of cowardice? I will show you the justice of the grave… and the true meaning of fear.” –The Lich King
“Did you think we had forgotten? Did you think we had forgiven? Behold, now, the terrible vengeance of the Forsaken! Death to the scourge! And death to the living!” –Putress
Remember, a safe flight is a boring flight!