Betty, Veronica and Archie Switcheroo

Meet Archie. He is your protagonist and by default the The Everyman. He is torn between two people: Betty, the Nice Girl, and Veronica, the Vamp who may be prickly and temperamental but is fun. Seems like a straightforward love triangle.

Or is it?

The Betty, Veronica, and Archie Switcheroo is when these roles are switched around. Sometimes Betty is revealed to have a hidden wild side or tragic backstory. Maybe Veronica is revealed to have Hidden Depths that put her in the Nice Girl territory. Perhaps Archie is actually a Bitch in Sheep's Clothing or isn't interested in either girl. In any case, the roles switch because people are not just flat characters.

Anime and Manga

 * Revolutionary Girl Utena has the titular character experience variations of this trope:
 * Utena starts falling for Akio, Anthy's brother. He seems much nicer than Touga, the Student Council president that tried manipulating Utena into losing a Rose Duel and becoming his girlfriend. Then Touga realizes that
 * Anthy at first appears to be the Archie in the relationship, as the Council members fight over ownership of her in mandated duels, with Utena serving as the Betty. It comes out that Anthy is more important than she looks; far from being a mere prize as the Rose Bride for the students to win, she's When the truth comes out,
 * Sailor Moon showed this happen in different ways:
 * Rei starts dating Mamoru in season one of the classic series. While she's portrayed as the Veronica to Usagi's Betty, in truth both of the girls bicker a lot, with Usagi sometimes having unprovoked jabs at Rei, and at this point Usagi has eyes only for arcade manager and Nice Guy Motoki.
 * In the anime, Makoto gets jealous when finding out that Motoki has a girlfriend, a Nice Girl named Reika who would be the Betty. Makoto would normally be the Veronica and prepares to sabotage the relationship, only to find out that she can't do it. When Reika is hesitant about accepting a job abroad that would separate her from her boyfriend, Makoto says that long-distance relationships work all the time, and encourages her that she and Motoki can still be happy, returning to their relationship when Reika's job is over. And indeed, when Motoki sees off Reika at the airport, both Makoto and Usagi are touched at how much the two care about each other
 * Yona of the Dawn has the titular character torn between her bodyguard Hak and her cousin Su-Won. Hak is Tall, Dark and Snarky who often treats Yona like a child, while Su-Won is always sweet to Yona and giving her lovely trinkets. Then Yona witnesses Su-Won killing her father the king in cold blood, on her birthday no less, and then trying to murder her as well; Hak selflessly risks his life to evacuate Yona and cannot understand why Su-Won would do such a thing. We also find out that the trope is more complicated; as a kid, Hak make Su-Won promise to marry Yona so they could all stay together, as friends.

Literature

 * The novel Fangirl (novel) has two instances of this:
 * Cather, the protagonist, is the Archie as she's attracted to both her roommate's boyfriend Levi, who is an older range management major that smokes and keeps inviting her to parties, as well as Nick, her quiet writing partner in class. Levi at first seems to be the Veronica while Nick is the safe Betty. Not that Cather is interested in either until her long-distance boyfriend Abel breaks up with her.
 * Meanwhile, Cather believes that she is the Betty to Levi, who is ostensibly dating Reagan, her college roommate that smokes, swears and kicks their door open a lot. She also says to herself that she is not interested in Levi because he is clearly taken.

Newspaper Comics

 * In Garfield's Nine Lives, during the Detective Sam Spayed story, Sam is torn between his Nice Girl secretary Kitty who makes great coffee and his new client, a widow named Tanya O'Tabby whom he suspects of killing her husband and using him as a Detective Patsy. Turns out that

Western Animation

 * Avatar: The Legend of Korra used Character Development to incorporate this trope with Korra, her crush Mako and his girlfriend Asami. It's a rare case when the protagonist is the Veronica, owing to her being the Avatar and having No Social Skills while Asami is the Betty: a Spoiled Sweet Nice Girl that sacrifices her cushy life to protect her friends from her turncoat father. Yet when Asami finds out that Korra kissed Mako, she doesn't blame the former and rightly susses that Korra doesn't understand romantic boundaries, while calling out Mako for not telling her. After more back and forth in season two, the girls finally talk it out in the season three premiere after they both break up with Mako.
 * In 'The Dragon Prince, Prince Callum at the start of the show is in love with his bodyguard's sister Claudia, a sweet girl that is a Cool Big Sis towards him and his little brother Ezran. He meets Elf Assassin Rayla when the latter hunts him down in a bid to kill Ezran, and he spends most of season one not trusting her, for obvious reasons. Season two has Callum and Ezran learn that Rayla was right that Claudia and her brother Soren found them in the mountains not to help them, but to take them and baby dragon Zym hostage to serve their father Viren, who wishes to usurp the throne. As they fly away, Callum has a heartbroken, betrayed expression on his face. Rayla spends the rest of season two and three dedicated to protecting the brothers, as well as Zym.