There are subjectives, and then there are these. While you may believe a work fits here, and you might be right, people tend to have rather vocal, differing opinions about this subject. Please keep these off of the work's page.
When Cirque du Soleil debuted KA in 2005, the aftermath of the Battlefield scene had the Emperor trying to comfort his wicked son, who has been blinded by his explosives and is crying in pain. Audiences laughed at the crying in what was supposed to be a sad scene, so this was dialed back.
Saltimbanco's climatic bungee act would be gorgeous if the singer didn't just... sit there and sing while watching the act.
Zarkana's baby funeral scene. "Welcome to my funeral, please don't scream..." Audiences find it hard to take seriously and have reportedly mocked it walking out of the show.
Many modern Shakespeare productions will have the characters transported to a modern setting or just without period dress. Generally, a lot of people find it Narmful to hear characters like Shylock or Prospero speaking in the 16th century tongue whilst dressed in jeans and a t-shirt.
"Now I am dead, now I am fled, my soul is in the sky..."
Essentially the entirety of that play was meant to be narm through terribad acting.
The last few scenes of Othello are ruined by lines like "I am maimed for ever" and "O heavens forfend us!" The latter is possible to say dramatically - but not in unison with somebody else, which is how it's supposed to be said.
Also in the end of Othello: Desdemona uttering a Final Speech after being suffocated. Suffocation kills you because of lack of air. Air is what you use to speak, Shakespeare.
Better in the opera Otello, when she has an entire aria.
The conventions of theater might mean that Desdemona's final speech should be taken as an internal monologue and not spoken dialogue. Shakespeare's characters love thinking out loud, and not every instance of that should be interpreted as literal speaking. Still, it's all too easy to interpret it that way...
Almost everything Gratiano says in that scene is obvious. For instance, he says, "He's gone, but his wife's killed" to describe an event that happened approximately one second ago in front of everyone.
Othello himself mars an otherwise magnificent speech in this scene with "Here is my journey's end, here is my butt..."
Not to mention the "O bloody period!" line.
Some of the deaths in Macbeth. Particularly "Fly, good Fleance, fly, fly, fly!"
Young Macduff: "Thou liest, shag-haired villain!"
Murderer: "What? You egg!"
Parodied in Horrible Histories, where the assassin says, "You've done it now, sonny! I happen to be very sensitive about my shag-hair!"
When the witches greet one another in an early scene and ask where they've been, one replies, "Killing swine." Now, while it was widely believed in Jacobean England that witches travelled the land slaying livestock, there's something about the bluntness of this line that makes it ridiculous.
After Macbeth and his wife murder Duncan, Ross and an old man take note of the ensuing dreary atmosphere. The dark skies and the owl killing and eating a hawk work well enough as symbolism, but the cannibalistic horses end up pushing things over the top.
From Julius Caesar, Mark Antony's famous "Dogs of War" soliloquy:
"O pardon me, thou bleeding piece of earth..."
This can evoke the image of Caesar as a human-shaped pile of dirt oozing blood.
Julius Caesar also features Cassius, who, upon hearing that it looks like the battle is going badly for his friend Titinius down the hill, kills himself. Titinius enters immediately afterward, perfectly fine. It's hard to summon much pathos for a death that could have been averted by waiting thirty seconds.
Titinius (or some soldier) immediately kills himself out of sorrow for his beloved commander Cassius. Like Hamlet, Julius Caesar is overly scrupulous about obeying the idea that tragedy means "everyone's dead by the end of the play".
Many of the Shakespearean examples are in the plays because they announce deaths and, without them, either the actors wouldn't know when to die or the audience in the nosebleed seats wouldn't know if someone had truly died. (That goes for the broken leg as well.)
Early Shakespeare has some truly beautiful Narm. In Henry VI Part 1, for instance, there is this hilarious line:
"O would mine eyeballs were to bullets turned, That I in rage might shoot them at your faces!"
The scene in Titus Andronicus in which Titus is presented his daughter, who had previously been raped and had her hands and tongue cut off/out:
"Titus, this is your daughter!" "Why, Marcus, so she is."
And then there's perhaps the most infamous stage direction in all of theater, from The Winter's Tale: "O I am gone for ever!" Exit, Pursued by a Bear. The bear is not mentioned at all in the prior speech and just comes out of nowhere.
For modern audiences, Aeschylus' play Agamemnon features a particularly hilarious bit of Narm. While being murdered offstage, the title character delivers this line:
Upon the revelation that Oedipus is her son, Iocaste immediately leaves the room. A servant walks in shortly afterward to report that the queen has committed suicide. You may or may not find the abruptness of all this hilarious.
An earlier scene also has Tiresias giving his signature warning to Oedipus while falling down and flopping around on the ground as though spontaneously getting heart attacks. The Chorus has to regularly push him back up, almost to the point of playing catch with him, and the fact that he's been made to look like some tremendous ghostly bird does not help.
Spring Awakening has the beating scene, which depending on how it's played, ends up being a Tear Jerker or terrible, terrible narm. Wendla giving Melchior a branch that she found on the ground and wants to be beaten with is a little much to take seriously.
"With this switch, for example?"
The entirety of The Duchess Of Malfi. You've got to love a play where someone gets poisoned by a Bible, there's an echo-ey grave, mad men are cavorting around outside a jail, the heroine holds a dead man's hand ... And a mad incestuous Prince thinks he's a werewolf and later says, "I account this world but a dog kennel." The Cardinal's reaction on being stabbed? "You have hurt me." Oh, dear. The doctor tries to cure Ferdinand of his madness and thinking he's a dog by... trying to fight him. Also, the number of people hiding behind tapestries. Special mention also to Bosola who is with both the leads when they die... and has howlers both times. With the duchess, he responds to her brief revival and subsequent final death with a mildly frustrated, "Oh, she's gone again!" With Antonio, he gets the following tactless exchange:
"Thy fair duchess and two sweet children—"
"Their very names kindle a little life in me."
Rent features a lot of people dying of AIDS and other un-fun things, so it's rather funny when people bluster in with comments like "Who do you THINK you are/barging in, on me and MY GUITAR?!" or just wailing out "MIMIIIIIIIII!" when someone's on their deathbed. The theatricality and over-emoting of musical theatre can make serious death scenes awkward. Never mind some of the goofy songs that were dropped from the musical during development, like "Right Brain".
In The Long Christmas Dinner Lucia says at several different points something like, "Such a beautiful sermon. I cried and cried." The first couple of times, it's moving— but after that, it just becomes a Running Gag.