iconic moments!

Thor toppling Arishem

Hulk's: "GIVE THEM BACK!" After the warp core went off

Not sure if iconic, but epic as all hell when Hulk broke Onslaught's armor

"The madder Hulk gets....the stronger Hulk gets...and Hulk is angry!" SMASH

Action Comics 1.

Cap punching hitler in the face.

Mon-El killing time-trapper.

Kal-L killing anti-monitor.

The death of superman.

Joker crippling batgirl.

Thor vs ultron, "We would've words with thee"

Superman vs mongul "Burn".

Superman vs Elite.

Onslaught taken the Cyttorak gem from Juggernaut

Superman vs Elite.
Death of Jean
Death of Superman.
Barry Allen sacrificing himself.

Reed making Galactus shit his pants with the ultimate nullifier.

Gwen Stacy dying, Bane snapping Batman's back

Death of Jean Grey
Emergence of the Worldbreaker (a scene that will give nightmares to the Hulk haters forevermore)
Owen killing pr Beyonder
Death of Steve Rodgers
COIE Cosmic Treadmill - something i'll always remember being the first thing comic related I ever read

Oh dear.

Did you really think you could do all this alone?

Take down forty Super-villains?

Talk about delusions of grandeur...

My name is Mysterio, the master of illusions.

My thanks on behalf of the criminal community.

Captain America verbally owning Thanos.
Thor's "We would have words with thee".
Cyclops deciding to give in to Emma's seduction.
Colossus' return from the dead and subsequent beat-down of Ord.
Hal telling Parallax to basically go **** himself.
Superman throughout all of OWAW.
Hulk winning over the people of Sakaar and choosing a wife, finally finding some peace.

The clash of Hotm Hulk and Betty....creepgrin

porn stars read that to prepare for a scene

surfer synthesizing the odin force

Darkseid first appearance
Darkseid mind ****ing Dessad by making him choose to kill his bird and forever made him sadistic.
Darkseid fighting out his wife, the only women he ever loved was killed by Dessad curtesy of his Mom because she believed he was growing weak
Darkseid poisoning his mom for revenge for killing his wife
Superman last out with DD in DOS
OWAW Superman weaping when he though Diana had died
Superman being afraid throughout the whole Hunter/Prey story line in coming face to face with DD, but knowing he had to do it for the greater good.

What is iconic for us, as in this:

Originally posted by dmills
Galactus' Herald My Rage!!!!

Nova tearing out Annihilus' guts, collapsing and seeing Thanos and Lady Death smiling at him then saying "better luck next time".

Or what is generally iconic/recognizable? Because some examples would be:

Superman crushing that car on the cover of Action Comics #1
Batman fighting Superman at the end of Dark Knight Returns
Superman dying fighting Doomsday
Superman's "Burn!" against Mongul
Bane breaking Batman's back
Batman finding Robin dead
The Killing Joke is one iconic moment itself, basically
Grant Morrison appearing in Animal Man
Ozymandias's "I did it 35 minutes ago"
Barry Allen sacrificing himself against the Anti-Monitor
Superman holding his dead cousing in his arms
Death of Phoenix
Hulk bracing the mountain in Secret Wars
Magneto pulling adamantium out of Wolverine
etc.
[yeah, Batman and Superman have a lot of those, it's not for nothing that they are the top 2]

Ben Grimm dying 2,000 years in the future as Franklin watched.

Franklin's big moment. "To me, my Galactus!"

Glen getting beaten to death in Walking Dead.

Carl and Rick getting brutalized in Walking Dead.

There are many, but the first one that always comes to my mind when thinking of classic, iconic moments is the whole sequence which begins with, "Within my body is the strength of many men," and ends with this:

This hit me pretty hard when it came out. Made me realize that even hero's can be pushed to far.

He stood alone at Gjallerbru...