In a flashback in the Thunderbolts 1997 Annual, Melissa Gold (in her costumed persona of Screaming Mimi, possessing sonic powers) obliterates a portion of forest, liquefies the ground around herself, and destroys her vocal chords upon the death of her boyfriend Angar, by falling to her knees and screaming for 48 minutes straight, until she shreds her vocal cords and can't do it anymore.. She gets better.
In an issue of the Sonic the Hedgehog comic (#135), this is Sonic's reaction to the apparent (and brief) death of his father, represented by him screaming helplessly with a big "N" and "O" to either side. It... doesn't really work. Points for trying, though.
In Batman: Year One, Gordon's reaction to his infant child being dropped from a high bridge. Luckily, Batman saves the day.
Batman: The Dark Knight Returns: The leader of the "Sons of the Bat" - Mutant gang members who have flocked to Batman (or their idea of Batman) as a symbol declares the blackout in the city as an ideal opportunity to Kill It with Fire. The Dark Knight's refutation is so stentorian that the speech balloon is in the shape of a Big No.
SotB leader: Gotham City is helpless — this is our chance to raze Gotham — to purge Gotham —
In Final Crisis, Overman's reaction to finding out his beloved cousin Kara Kant/Overgirl is dead. Since he's German, he goes "Neinnnnnn!"
When Jane Foster is killed (don't worry, she gets better) in The Mighty Thor #371, Thor spends an entire page smashing stuff up while shouting "NO!". He ends up kneeling in the wreckage, saying one final, very small, "No."
Omniscient Narrator: You and the X-Men have saved the world from a nuclear holocaust, but you lost a man to do it...and try as you might, you can't balance those scales in your mind or in your heart...can you, Cyclops?
In "The Haunted Sky" in Creepy #30 a test pilot yelled one when the ghosts of buddy pilots from the wars he'd served during made him crash his plane.
In "Lifeboat" in Creepy #34 the last survivor of a dead race yelled one when he was tossed out an airlock.
Amelia from Amelia Rules! screams a NO! that fills an entire page after regretting that she gave up her spot as a cheerleader to her friend Rhonda.
X-Men; in the story "Kill or Cure"; from Iceman , when Mystique reacts badly to his final rejection of her (she jumps off the San Francisco Bay Bridge).
The Golden Age: Thunderbolt, when his master Johnny Thunder gives him the command to kill Hourman during the Dynaman revelation incident, became so conflicted with that and his own personal ethics that he just departed from the scene entirely, screaming this.