In Tales for the Leet's Romeo and Juliet, Juliet has an especially Big No after finding Romeo dead, taking three lines of dialogue to complete and ending with multiple !s and 1s.
A Crown of Stars: Asuka combined this trope with Rapid-Fire "No!" in chapter 5. When Asuka insists that she does not need anyone and she has an agreement, Daniel points out that it is very fragile and she fears that it will not last... And then what? She will try to kill herself again?
She hadnt cried, not even the day they buried her Mama. She would not cry now. She would not. Dont take him away. I dont want to be alone. I dont want to be alone. I dont... ...need anyone. My arrangement- Is a hollow shell, that you both fear and expect to collapse at some point. Then what? Water again? Or this time the barrel of a gun in your mouth? Daniel said quietly, his words hitting Asuka harder than if hed been shouting them. Or a twist of hemp like your mother, feet in the air? NO! Nononononono! I...I...STOP IT!
Advice and Trust: In chapter 4 Asuka shouts one when a classmate severely misunderstands Rei's words:
Rei:"Though I believe this bond predates that session. Ikari is the first person Pilot Soryu ever let inside her Entry Plug." Tanaka:"Is... is she talking about-" Asuka:"NO,"
HERZ: Exclaimed by the SEELE members when the Children took control of their newest MP-EVAs.
The One I Love Is: When Shinji saw the MP-EVAs had chopped Unit-02 into pieces and possibly killed Asuka he screamed a very big and anguished "no":
I opened my eyes and then saw a scene that will probably haunt me the rest of my life. I saw nine white EVAs, circling around what was left of Headquarters. And in their hands, or even worse, their mouths, they held the remains of what had once been Unit-02. "NOOOOOOOOOOOOOOO!!!!!!!!!!"
In A Day in the Life of a Commissar, a Dawn of WarMachinima, Commissar Steeve does this when he's told Galactic Starbucks is out of coffee. He stops to ask "Really? What kind?" once he's told that there is, in fact, some coffee left. And finishes when he's told it's decaf.
In Deserving, everyone has No Indoor Voice especially when uttering the word "no", which appears in ALLCAPS as often as not.
In Revenge Road, Kyosuke wakes up after realizing that the previous events, Hikaru killing him and Madoka was All Just a Dream. Madoka then gets up to answer the door, like she did before, and when Kyosuke realizes what time it is, he runs down the stairs yelling "Midnight? Oh no! Madoka! StOP! NOOOOooooooo!", only to find that he is too late as Madoka gets shot and the fic ends.
This occurs twice in Oh God Not Again!; once by Fred and George when they see the Quidditch field is now a hedge and again by Harry when he finds out Hermione won fifty points (again) after he dedicated himself to losing the House Cup.
In Losing Control Voldemort and all of his Death Eaters yell one when Azrael announces that as punishment they'll have to spend the next thousand years serving Muggleborn as house elves.
In Harry Potter and the Fold Harry yells one after a nightmare where the ghosts of Cedric and his parents say he should've died in their place and the figure coming out of the cauldron after Voldemort's resurrection is himself.
In Nobody Cared Snape yells one during a nightmare about Remus almost killing him during his sixth year.
In Emancipation Hermione yells one when Macnair kills Crookshanks.
In Snape's Worst Nightmare, chapter 7 ("Them v Us"), Snape lets out a huge "NO!" when Isabella Weasley manages to get the Snitch in a game between the Weasley-Potter team and the Slytherin team. He had bet Harry that he would never punish the Weasley-Potter cousins if they won.
A meta example from Harry Potter and the Methods of Rationality: Early in the story, based on the Quibbler headline about how Harry gets Malfoy pregnant, the author got several e-mails asking if Luna was a seer, and if the story was going to turn into an HPDM bottom!Malfoy mpreg fic. The author regretted that fanfiction.net did not allow a larger font with which to say NO.
In The Circle Fred and George yell a deliberately melodramatic one in unison when Dumbledore announces the cancellation of Quidditch at the start of Harry's fourth year.
In Harry the Hufflepuff 2 Harry yells one when the conductor of the Knight Bus realizes that he forgot to switch the bus out of "night mode" and all of the beds are replaced with uncomfortable-looking wooden chairs.
In Not the Only Redhead Mrs. Weasley yells one when Bill and Charlie are arrested on suspicion of having beaten Harry half to death in Hogsmeade.
For a more humorous example (ironically in the Crapsack World of the Dark World arc), when Twilight asks The Voice whether it's some repressed part of Discord fighting against himself, it replies with one of these loud enough to leave her cross-eyed and temporarily aphasic.
Everyone's response to when, after the Grand Line's weather between Reverse Mountain and Whiskey Peak, Zoro complains about them waking him up for that and asks if they could have handled it themselves.
This is the crew's response when Cross breaks out the Stink Bomb bug repellent lotion on Little Garden. Cross vetos it.
This is the crew's response when Cross threatens to use his new foghorn to make an enraged Nami calm down enough to listen to reason.
In With Strings Attached, at the climax, when it becomes clear to Kerrun and Sapsa that the four are going to make off with the Vasyn, they scream No! To which the four triumphantly respond with a Big "YES!"!
"Are we there yet?" Bobby Drake whined for about the thousandth time. Scott Summers just sighed. Hank McCoy rolled his eyes. Warren chuckled humorlessly to himself and Jean was going to start losing her temper. "NO!" Was the reply that quickly came from all his teammates.
In Neither a Bird nor a Plane, it's Deku!, Hisashi Midoriya combines this with Rapid-Fire "No!" while arguing with his wife about adopting the baby alien he and his wife fished out of the crashed spaceship near Mt. Fuji, punctuated with a stream of fire from his fire-breathing Quirk.
Hisashi: No. Inko:[about the baby] He looks like a normal baby- Hisashi: No. Inko: -and everyone's probably looking for a big, green, monster man. Hisashi: No. Inko: It's hard to find something when it's hiding in plain sight- Hisashi:Nonononononononononono- Inko: -so if we don't want anyone to know we were involved in this, I was thinking that- Hisashi: NO! [stream of fire shoots out of his mouth]
All Might has this reaction after the Ultra-Humanite blasts Izuku off Mt. Fuji, quickly following this with a This Is Unforgivable!.
In A Prize For Three Empires, Carol Danvers lets one out, combined with remorseful tears, when she finds out Zenith, a Shiar guardsman she killed during a battle, was her friend Razas brother:
Warbird looked up, her eyes closed and tearing, her fists clenched, and shouted one great word that filled the cabin. "NO!"
X Men 1970: Uttered by the leader of an extremist group when Cyclops asks if fear of being conscripted is his chief motivation.
Cyclops: So, you're doing this because you're afraid of the draft? Carter: NO!
In Hellsister Trilogy, Linda Danvers introduces her new beau Dev-Em—who is secretly a 31st century Legionnaire—to her landlady Ida Berkowitz, who grows concerned with Linda dodging every question regarding her new boyfriend's mysterious personal life. So, when Ida asks if Linda could take her to his workplace...
Ida: Seems to be hiding something. 'Security consultant'? So all right. Maybe he is. Maybe he's got to be Mr. Secret to do his job. You sure this is really what he does? Linda: Sure as I can be. Ida: Like how? You been to his place of business? Could you take me? Linda: NO! I mean, yes, I've been there, and no, I couldn't take you. He made an exception for me.
This is Damian's reaction when he's told Bruce and Selina are expecting a baby, early in Batman: Grudge Match. At the start of the next chapter, Alfred is sweeping up glass from a window, implying Damian's scream shattered it.