Wham! Line/Fan Works

"Shinji:"
 * "No, John. You are the demons."
 * RE-TAKE: "You are an Angel."
 * More than there were before.
 * NGE Peggy Sue fanfic The Second Try pulls a nasty twist at the end of Chapter 5:

"Kaminic: Thank you. If it hadn't been for you, I would have remained a slave for the rest of my life." O.B.A.M.A.: You, You're..." Kaminic: "The only Absolution given form. The Former God of Water. The Aspect of Evolution. The Name of A Thousand Suns. I am the Alpha and Omega, Beginning and End, I am HE Who is CALLED I AM, you arrogant bastard. I am the Logos, the Garden, the Primal Meme. I am Kaminic. And, I am your death.""
 * Forward: "Inducer One-One-Nine. (...) Kathryn Wade. Katie."
 * Mass Vexations: "You don't fucking understand! I knew she was going to fucking die since I fucking arrived on the fucking Citadel!"
 * Tiberium Wars: "You can call me LEGION."
 * Fuck the Jesus Beam: " Are you kidding me, girl? I've been in stasis for over a HUNDRED MILLION YEARS. If anyone threatens my domain, they -will- die. But first, I shall reclaim it."
 * Chapter 8:

"Mackie: Oh my god! I know where she's going! Home! The Nyarlathotep is going home!""
 * Relationships Series: "I think...you need to break up with Wendi and Nove, now."
 * Renegade: "You can't kill the Messiah."
 * My Immortal: "Very well [...] Butt we cannot do this. We can’t close the school. There is only one person who is capable of killing Voldemort and she is in the school. And her name is…………………………………………………………………..Enony Dark’ness Dementia Raven Way."
 * In Derelict, Lieutenant Mackie figures out what the SD Nyarlathotep is trying to accomplish after forty-five missions of complete mystery.

"Blud: "THAT'S WHERE YOUR WRONG MY SHINY HAIRED APPRENTICE. YOU SEE I ONLY PRETENDED TO BE YOUR SHINIGAMI BUT IN FACT I WAS L'S ALL ALONG. I GAVE HIM A LIFE NOTE AND ALL I HAVE TO DO IS WRITE L'S NAME IN IT AND HE WILL COME BACK TO LIFE AS GOOD AS NEW AND YOUR PLANS WILL HAVE BIN FOILLED!""
 * Kyon: Big Damn Hero: "Not half as monstrous as that thing you're trying to kiss."
 * Pokemon XD^3: The Waves of Truth: It becomes pretty clear early on that Chapter 21 is a Wham Episode, but you can literally feel the trajectory of the entire story change the moment the doctor tells Rich that Anabel just miscarried twins that he didn't know about.
 * Light and Dark The Adventures of Dark Yagami: Chapter 6:

"Dark: "r u l lol?" L: "yep""
 * Chapter 14, after Dark finds some familiar age/sex/location information on a Talk to Dead Dudes Note.

"Fate: "I'm sorry, I can't. Mother, did you know you had a split personality disorder?""
 * MGLN Crisis Chapter 25:

"Gordon Freeman: John Freeman you let next boss step on me and made me headcrab zombie. Combines came and put science in me and made me live and strong and big now. I make you and Henry Freeman headcrab zombies. Prepair to die."
 * Half Life Hero Beggining: "Combines leave my son alone" John Freeman said.

"Raonar: Ladies and gentlemen… I have just made the Archdemon smarter, and if it was not self-aware before, it definitely is now."
 * The Coraline fanfic Right Beside You has two WHAM lines:
 * Chapter 9: "Yes Coraline, I am the boy's father."
 * Chapter 12: "… No, Richard. I'm not satisfied… at all."
 * TDWT Reducks Redux: "It is within my power to remove you from the position of host."
 * From the Homestuck/Problem Sleuth crossover The Sapphire of Alternia:
 * Chapter 15: But the realization you’re actually having is that this case is just like all your other cases: a quarrel between a married couple.
 * Chapter 24: The Sapphire of Alternia is the White King’s Scepter.
 * A crossover story between Code Geass and Mobile Suit Gundam 00 on the Anime Addventure features this Geass command by Rai on Setsuna for an experiment: "Setsuna F. Seiei, I command you to believe in God!"
 * It was such a shocking command that a reader commented that he jumped in his seat!
 * Dragon Age the Crown of Thorns:

"Madara: JAKE! U MUST KNOWETH SOMETHING! TALIANA! SHE IS THOU MOTHER!""
 * Avatars II When Qwaritch Takes Revenge In the third installment, when Quaritch hears about the Navi harem. ("His(sic) room on your left is the Navi harem.")
 * Naruto Veangance Revelaitons: "well, u c that was an anitdote 2 wake her up, but it also terns hur...CHRISTIN!"
 * Chapter 14

"Madara: "YES! U WILL NEVR MAKE IT 2 DA COUMCOLS ROOM!" Ronan: "THA COUNCIL? IM LOKING 4 SAKUR!" Madara: "OH WELL DEN UR IN 4 A SURPRIS... 4 U C DIS IS THJE CUNCILS HEADQURTES!""
 * This exchange.

"Hello. Do not adjust your computer screen... for it is I, Benji (that guy Jake bitches about all the time)!"
 * At the end of Chapter 49, the Council declares that they will resurrect Sakura if Ronan wins their tournament. What makes it a Wham line? Sakura isn't dead yet, and is killed immediately after they say this.
 * This line from Chapter 70, or even the presence of a Chapter 70 in a fic that was set to end after 69 chapters.

"...I'm not a virgin."
 * Thanks☆Kyubey: "...Good. It looks like our experiment was a success."
 * Hunting the Unicorn, chapter eleven:

" Having a rough patch, Tom?"
 * And in the twentieth chapter:

"Still, maybe she [Rem] was wrong about L...maybe she shouldn't have killed him..."
 * Soul Chess: "Aizen! Kill yourself!"
 * When There Was a Tomorrow: We're given the line "For now simply know that your prior feelings when we first met were understandable and I do not think poorly of you for them." Now, what makes this apparent Character Development laden line so surprising? What makes it even Whammier is that when Tali points out this change in behavior   insists it's not calling itself   and seems genuinely unaware that   doing so. The exact significance of this line has yet to be seen, however.
 * With Strings Attached has two:
 * “The biggest thing is that there really isn't a curse on Ketafa.”
 * “It's all been a real game, hasn't it.”
 * Death Note fanfic Xanatos starts off with L reconsidering his method of catching Kira, and so striking a deal with Rem. We're made to believe that she went along with his plan after L fakes his own death, but then chapter nine gave us this:

"I can help you...with your Horcruxes."
 * Harry Potter fanfic Pretending to Live has the main Original Character drop this one on a sixteen year old Tom Riddle:

""We're the only ones left." "Neither of us killed it... you did.""
 * Two in rapid succession at the end of Stars Above Chapter 4:

"Applejack: AH AIN'T SAY YA LYIN'! YA ARE A LIE!"
 * Pony POV Series, "Playtime":

"Shinji: (to himself) "Well, at least (the next world) can't be as bad as the one I just left, right?" Cute red-headed young woman with horns: "N yu?""
 * Don't Name It: You once again try to be the Jade Blood. And fail spectacularly.
 * The Neon Genesis Evangelion Crossover fanfic Birth of a God ends its prologue chapter with one of the most epic Tempting Fate -> Wham! Line combinations ever.

"Phoenix:"
 * In Turnabout Storm, Phoenix needs to stall for time in order to get more evidence to clear Rainbow Dash's name. So what does he do? This:

" " she is right."
 * Futari wa Pretty Cure Blue Moon: "If you won't take my word as, then take it as , alright?"
 * A Complete Turnabout

"Firefly: Because... he... he...!"
 * Anthropology: "You weren’t born here in Equestria, Lyra.”
 * Ace Combat: The Equestrian War:
 * Chapter 7, when Firefly tells her friends why she hates the griffins and why she's upset upon seeing Black Star:

"Black Star: (to Edge) . Let her know that."
 * Chapter 16, when Black Star tells Edge to deliver a message for Firefly:

"Shizune: I hit 'Send' as I turned the handle and walked in on Shiina and Hisao."
 * In the popular and acclaimed Avatar: The Last Airbender series Alone: From chapter eleven - The second being a sudden revelation of a Time Skip, akin to a certain scene from Order of the Stick.
 * From the Katawa Shoujo fic, From Shizune's perspective

" : Hermione Granger, you're"
 * Harry Potter and the Methods of Rationality:

"Mai: You see all those years ago, when I got to your letter, something had to be done. You where not sick... like I wanted everyone to believe... I had made something just for you to eat so that little problem would go away... and yes, I took pleaser in doing it..."
 * How I Became Yours

"Lilly: "I-I’m sorry, but ""
 * Reconciliation
 * Chapter 3

"Sho:"
 * Chapter 8

"Masaru, a.k.a. : Uchiha Yumi...I swear by this blood that I will have my revenge for ]. Every drop of blood that your spilled will be repaid ten times over. I denounce you, Uchiha Yumi, you and your entire family as hypocrites and murderers. From this day forth, I and my children will never eat with you and yours. I arm myself against you"
 * Hakumei: (extra jarring considering he's essentially leveling a blood feud against his own clan)

"Gregory: Here's the really unpleasant part Warwick. How many families do you know with that old photo on the mantle and the child who they don't talk about anymore?"
 * The Shadow State:

"Sol: (jokingly) Maybe they're Jovian!"
 * Clear Skies 3

"" ""
 * The Doctor Who fanfiction Of More Value Than Many Sparrows, in which

""This explosion would be seen from several cities away, and it was something that they would never forget. It would also commemorate something else. That day was the day that"
 * Poke Wars has quite a few of these:
 * From The Coalescence:

"Regigigas: "Ho-oh, it's not a matter of wanting to give you the orb, ""
 * From The Incipience:
 * Chapter 7:

""'Hmm…how unusual. How did this get here? Interesting. Wonder if this machine is capable of creating this. Will have to see. Interesting prospect, may open new doors. Will have to keep this secret. Ho-oh's shortsighted hatred may make him blind to the possibilities this subject can create,' Uxie said to himself, looking at ""
 * Chapter 9:

"Darkrai: """
 * Epilogue:

""Butterfree's Protect held for exactly five seconds.""
 * From The Exigence:
 * Chapter 4:

"Houndoom: """
 * Chapter 7:

"Uxie: "Muk thrive in areas of waste. Unwanted by humans in cities and unwanted by Pokémon in wild. Coexistence with others in wild difficult due to neighboring Pokémon exhibiting heightened senses of smell. Not uncommon for Muk to be forced into city by aggressive Pokémon in wild. Muk typically forced to live in sewers beneath city to avoid human aggression. Limited light. Limited mobility. Dampener removal and message from you initiated desire to take and expand territory. Despite our eminence, chances of reasoning with them to stop are…low. ""
 * From The Defervesence:

"""
 * Clash of the Elements
 * From Part 2:
 * Chapter 24: