Films routinely deal with Love Triangles. Fans sometimes disagree with the resolutions violently.
Will Turner from Pirates of the Caribbean. Ever since he married Elizabeth Swann, many viewers who wanted Elizabeth to be with Jack Sparrow are making him out to be a rapist, an abuser, too "nice" so the Super Bad Boy is OMG better, or both.
Calypso gets this from Davy Jones fangirls, who make her a horrible bitch. Granted as a pagan goddess and physical manifestation of the ocean she was hardly the most sympathetic character in the movie, but that's ignoring the fact that Jones himself wasn't very nice in turn (having her magically bound to human form, which she describes as "torture") as well as the fact that she clearly did still love him and was horrified to hear what he did to her. One Mary SueSelf Insert fic has said Sue actually kill Calypso, and be treated as a heroine for it. Which goes against everything in the trilogy's universe, but logic be damned.
This trope is inverted for Corpse Bride: Victor/Emily shippers want Victor to die — because Emily is dead from first meeting. That said, there has been a fair amount of vilifying of Victoria in post-film Victor/Emily fanfics, portraying her as a gold digger or just plain mean to Victor. (And it can probably be argued that leaving Victoria at Barkis's tender mercies in some AUs is A Fate Worse Than Death.)
Ever since The Lord of the Rings books were made into movies, Arwen has been loathed by Éowyn teenyboppers who see her as the obstacle for Éowyn to get Aragorn's love, or as a "bad, bad, girly girl". The Aragorn/Legolas slashers also have it against her. The animosity towards Arwen since the movies continually frustrates many book!Arwen fans.
Faramir also gets some flack from rabid Aragorn/Éowyn fans, who see him as being less worthy of her than Aragorn. Never mind that Aragorn himself sank that ship by pointing out how unhappy Éowyn would've been if she married him, and later was very happy when she and Faramir became the Beta Couple...
And both Éowyn and Arwen catch heat from the Mary Sue creators who ship their unholy spawn with Aragorn or Faramir. They get even more from the Yaoi Fangirl contingent who must have Aragorn sidling up to Legolas. (Or Boromir, which is a doomed relationship if you don't go severely AU.) In one fic, Arwen was turned into such a shrill harpy that, in a post-series tale set in the present day, she sold the mummies of her and Aragorn's children to a museum just to hurt him. (Seriously.)Éowyn is likely to get written off as "that butch chick".
Adding to the weirdness factor of the whole Aragorn-versus-Faramir argument is the reason that Tolkien didn't stick with his original Aragorn/Éowyn. Faramir is an Author Avatar, and reportedly, Tolkien grew to love the character of Éowyn so much that he changed his plans just so she would end up with his Middle-Earth doppleganger.
Not to mention, Aragorn himself sunk the Aragorn/Éowyn ship by telling Éomer after he heals the almost fatally injured Éowyn that she was more in love with the *ideal* represented by Aragorn, rather than Aragorn himself. And to put the final nail on the coffin, Aragorn also adds that Èowyn would've been incredibly frustrated and even unhappy in the end, if she married him. OTOH, the book (and IIRC, a scene in the movie's DVD edition) shows that Éowyn and Faramir fell in love after they bonded over their emotional troubles and got to know each other better.
Don't forget the Sweeney Todd Sues, who somehow manage to become Sweeney's truest of true loves ever, even though (A) he was utterly devoted to Lucy throughout the movie and (B) Sweeney was very much anti-touch. One such Sue actually got Sweeney to denounce his love for Lucy and Mrs. Lovett after both were dead, in favor of said Sue.
Due to Bollywood marketing being dependent on which combo of actors and actresses is the screen couple (referred as a "jodi" by Indians and the Industry), fans of a particular screen couple (who often do several movies together if successful) will fight fans of another couple. Shah Rukh Khan/Kajol is the quintessential example these days.
A certain portion of Kirk/Spock fans have had quite a bit trouble dealing with the fact that in the 2009 reboot movie Spock/Uhura is canon, and some rather nasty stuff has been said about Uhura as a result.
A good number of fans ship Hiccup with Toothless (yes, the dragon) or Tuffnut (Ruffnut's twin brother) with as vehement loathing of Astrid, who tends to get labeled as shallow for showing interest in Hiccup after finding out about his dragon, even though she was the only teen that did not actively mock/tease Hiccup in the beginning and thus had less of a personality shift than the others would have.
Many fans of A Knight's Tale would have preferred that William ended up with Kate rather than Jocelyn. Also uses "feminist" bases since the fans like to take the Plucky GirlWrench Wench and then "give" her William as a "prize" for being a "strong female and so unlike the Jocelyn bitch"... when if they believed in Kate's strength as a character as much as they said, they wouldn't feel the need of making Kate's overall happiness depend oh so much on whether the hero liked her or not rather than on other things like her own blacksmith work.
One particularly nasty Labyrinth fanfic had the author's Self InsertMary Sue have Jareth declare that he never loved Sarah and marry her and then literally has Sarah die for the ship. Yeah.
In Newsies Sarah is portrayed as whiny and annoying so that way Jack can get with someone else, usually a Self InsertMary Sue. Or David.
Poor poor, poor Carly Spencer. It's bad enough that fanboys want the actress who plays Carly (Rosie)'s head chopped off for replacing Megan Fox, (something that Rosie obviously has no control over, she took the role, as any sane person would do if they were offered a role of a lifetime in a big budget movie like the 3rd Transformers movie), but according to hardcore SamxMikaela shippers, she is ugly (Yes the Victoria's Secret Model is ugly...don't think to hard about that), evil and the anti-christ who should be burned. It doesn't help that Mikaela is only mentioned in passing in the 3rd film, and it's implied that she dumped Sam because she only liked him for his involvement with the Transformers...
