"She wears short skirts, I wear t-shirts She's cheer captain and I'm on the bleachers" —Taylor Swift, "You Belong with Me"
One of the most common types of Love Triangle, named after characters from Archie Comics, wherein the main character ("Archie") is caught between two love interests with drastically different personalities. "Betty" is the sweet, reliable, everyday Girl Next Door type (which could mean "kind of dull"), while "Veronica" is more alluring, exotic, and edgy, but has more of a mischievous or icy personality (which could mean "kind of a bitch"). This translates to their physical appearances; Betty will be pretty but modest in dress, while Veronica will be Ms. Fanservice in all her glory. As a rule, they will have different hair colors as per the Blonde, Brunette, Redhead trope.
This trope is almost endlessly flexible. In a commonly-seen version, Betty is Archie's loyal comrade and usually his best friend, secretly pining for him while he (unaware of her feelings) is attracted only to Veronica, the sultry Ms. Unattainable who barely notices him. Betty, who wants Archie to be happy, may assist him in his pursuit of Veronica, even though we all know how much she wants him for herself. Another possibility is that Archie and Betty are already in a relationship, but then Veronica starts batting her eyelashes at him (or her!), causing friction between the couple. In cases of Arranged Marriage, Betty is the girl the parents prefer and Veronica is the one they reject, especially if children are expected (because Betty is more likely to want them). When Archie meets Betty and Veronica at the same time — if they are sisters, for example — he will fall in Love at First Sight with Veronica and only notice Betty after she had time to grow on him (as, for instance, when he often comes to their parents' to try to woo Veronica).
"Archie," "Betty," and "Veronica" can be any gender or orientation, though The Gentleman or the Scoundrel is a possible Spear Counterpart specific to the situation of a female Archie and two male suitors. Another variant is Rich Suitor, Poor Suitor, with a rich but douchey "Veronica" and a poor but kindhearted "Betty", or a rich and kind but boring "Betty" and a spirited blue-collar "Veronica."
Whom the hero will end up with varies according to medium, story, and the values of the time period and culture where the story was made. Traditionally, Betty stood a better chance, at least if the story had a Happy Ending, due to conforming to social standards, while choosing Veronica would only lead the poor sap into ruin. Usually, the hero would spend the story chasing Veronica only to realize that Betty was The One — complete with a convenient 'appreciate what you've got' or True Beauty Is on the Inside Aesop. However, as attitudes to what is 'appropriate' sexual conduct have liberalized, it's more accepted for Veronica to have a chance at winning a happy ending too, if not with the main hero, then as part of a Beta Couple. Movies have traditionally favored Betty, but video games, comics, and TV shows (especially long runners) have played this trope for all it's worth. In genderflipped cases, the Veronica usually has the edge, especially if the story is aimed at women, and if the (male) Betty wins, you can bet the fanfic writers will race to fix that.
In case this wasn't complicated enough, sometimes a Third-Option Love Interest makes their presence known to shake things up even further. Look up Cock Fight for the almost-literal Spear Counterpart.
Movies have lately come to a compromise with the Manic Pixie Dream Girl; cute and non-threatening, yet exciting and different. Video games with Multiple Endings get to Take a Third Option by letting the player choose who the hero ends up with. Comic book and TV show franchises tend to have Negative Continuity over the long term due to constantly rebooting their origins to avoid Continuity Lockout.
Compare the admirable one and sexy one of the Four Girl Ensemble as well as the wife and seductress of The Three Faces of Eve. Betty might be the Light Feminine while Veronica is the Dark Feminine in Light Feminine and Dark Feminine.
Do be aware that fans like to exaggerate potential relationships; Shipping would not exist without it. As a result there are likely to be multiple instances of an Official Couple (vindicated by Word of God) that has some sort of Fanon-based "romantic rival" mirroring this trope. Even shows without such romantic entanglements in-universe can inspire Betty/Veronica debates amongst the Fandom; hence, Mary Ann/Ginger, Bailey/Jennifer, Janet/Chrissy, Velma/Daphne, etc.
A very small number of these scenarios, particularly in more recent times or exotic settings, the Betty and Veronica conflict may be resolved by the triangle becoming a One True Threesome, or giving them a Marry Them All ending. This is particularly prevalent in fan works.
See also Betty and Veronica Switch, where the presumed Betty and Veronica somehow switch roles.
Card VI "The Lovers" of the Tarot has, in many versions, the imagery of an Archie who needs to choose between a Betty and a Veronica. It's meant to represent the choice between sense and sensibility, etc.
In "The Wooden-Clog Maker and the King's Daughter", the clog maker is in love with Guilemette, and both of them too poor to marry, when he receives a tree that has peaches in the middle of winter. He is diverted from her by learning the king will marry his daughter to whoever brings him peaches in mid-winter, and tries the Impossible Tasks the king sets, but in the end rejects the princess for Guilemette.
In "The Damsel With the Long Nose", in the beginning, the simpleton lad helps a miller's daughter, who gives him three things that turn out to be magic. (The narrator observing at the time that he should have stayed put with her.) A princess tricks him out of them, one by one, but is so beautiful and charming that he keeps trusting her again. Finally, he gives her a long nose, which makes her so ugly he falls out of love, and tricks the things back out of her — and then wishes himself back to the miller's daughter, since she was kind and simple.
Even shows without such romantic entanglements in-universe can inspire Betty/Veronica debates amongst the Fandom; particularly if there are two main female characters who fit the Betty/Veronica archetypes.
Teen Titans. Fans who ship Beast Boy/Raven will often portray Beast Boy as Archie, Raven as Betty, and Terra as Veronica. In Fanfiction, Beast Boy will be more taken with the unstable, traitorous Terra, but in the end he will discover that he's loved his friend Raven all along.
In an odd contrast to this lyric, Veronica was actually a big-city debutante in her initial introduction in the 1940s, in order to contrast with small-town Betty.
Dolly Parton's famous song Jolene paints the picture of this variety of love triangle. Jolene (with her "beauty beyond compare") is the Veronica, and the singer (who "cannot compete with you, Jolene") is the Betty. The song consists of "Betty" begging Jolene not to steal her man.
Samantha Echo's "I Wanna Shake her Hand" is a Betty and Veronica song from Veronica's point of view, in which Veronica is sizing up Betty in a sarcastic, passive aggressive manner. Betty is the wife of her married crush (Archie), who looks at her (Veronica) as if she is "a strange, forbidden door." The sexually frustrated narrator vacillates between feelings of jealousy and friendliness, which is particularly evocative of the trope namers, who were actually best friends when they weren't fighting over Archie.
Taylor Swift's "You Belong With Me" features a love triangle between blonde Girl Next Door Taylor Swift and a dark-haired cheerleader rival... also played by Taylor Swift.
In one of her lesser-known songs (The Way I Loved You) Taylor Swift takes the role of Archie choosing between her current boyfriend (Betty) who she describes as 'sensible' and who 'calls exactly when he says he will' and her 'wild and crazy' ex who is 'just so frustrating, intoxicating, complicated', who fills the role of Veronica. In the end, she chooses her ex.
"The Boy is Mine" by Brandy and Monica. While this isn't explicit in the song itself, if you look at the ladies' individual musical styles, Brandy is more a sweet girl-next-door while Monica has more of a street edge.
The video clip of Avril Lavigne's Girlfriend depicts Avril (as the Veronica) convincing the Archie to leave his uptight Betty girlfriend for her more interesting, more bullying self. Veronica wins.
Bryan Adams's "Run To You." The Archie sings about cheating on his Betty-esque girlfriend with his Veronica.
"She's got a heart of gold, she'd never let me down/ But you're the one who always turns me on, you keep me comin' 'round."
The Statler Brothers' 1972 country hit "Do You Remember These" has a quick line, "Veronica and Betty" toward the end of songs, part of a longer list of 1950s nostalgia.
Saving Jane's "Girl Next Door" brings up the singer as the Betty and her rival who is the Veronica.
The 1962 Marty Robbins hit, "Ruby Ann," tells the story from the point of view of the male Betty. He is a poor but honest, loving man. Ruby Ann is the female Archie who chooses him over the "big man" male Veronica. As the Betty gloats, "Big man, you got money in your hand, so what? You're at a table for two, but still there's only you, big shot....Ruby Ann took the hand of this poor, poor man, ain't true love a funny thing?"
The Carl Smith classic, later covered by Mickey Gilley, "I Overlooked an Orchid (While Searching For a Rose)" tells of the singer's bitter disappointment after choosing the Veronica, whose exotic but superficial beauty didn't last. Betty (the orchid) had true beauty that has stayed the same through the years.
In Wicked, Fiyero and Glinda initially bond over their self absorption and love of living it large. They start going steady. Elphaba realises she loves Fiyero the day they rescue the lion cub, he starts to realise he has feelings for her ... It sorts itself out for the best eventually.
And then Elphaba and Glinda got Word of Gay'd. Yeah, it's complicated.
It's usually safe to assume that Everyone Is Bi in a Gregory Maguire story unless explicitly stated otherwise.
It's kind of hard to say which girl is the Betty and which is the Veronica, though. If we define the Betty as the humble, relatable one and the Veronica as the glamorous, enviable one, then Elphaba would be the Betty and Glinda the Veronica. But if we define this trope as "safe choice vs. edgy choice," then the adorable, popular Glinda would be the Betty and the fiery, freakish-looking outlaw Elphaba would be the Veronica.
There's also a secondary triangle with Boq, Glinda, and Nessarose, which is similarly subverted. Boq is in love with Glinda (Veronica) who isn't interested and tries to pawn him off on Nessa (Betty). Nessa, however, turns into quite the Clingy Jealous Girl and morphs into the Veronica.
In Georges Bizet's opera, Carmen, Don Jose has Micaela, his sweet friend from his hometown who tells relays messages back and forth between Don Jose and his mother, and the title character, who is a free-spirited, dangerous Hot Gypsy Woman.
In Lady in the Dark, Liza Elliott, editor of Allure magazine, is unable to make up her mind between Kendall Nesbitt, the publisher who started the magazine for her, and hunky Hollywood actor Randy Curtis. She finally decides to reject both and Take a Third Option.
The Rainmaker has File (a Betty-type) and Starbuck (a Veronica-type) as rival love interests for Lizzie (same goes for The Musical version 110 in the Shade).
Thirteen has Brett in a Love Triangle with Kendra (Betty) and Lucy (Veronica). Meanwhile there's a friendship version of the trope where Evan has to decide between being friends with Brett and the cool kids (Veronica) or with the losers Patrice and Archie (Betty). Then there's a subtle one of Kendra liking Brett (Veronica) while being oblivious to Archie (Betty).
The Wildhorn musical adaptation of Jekyll and Hyde has the aristocratic Emma Carew as the Betty and prostitute Lucy as the Veronica. Several screen adaptations of the story have also used the trope, with Jekyll's fiancee (usually the daughter of Sir Danvers Carew) as the Betty and a prostitute/bar girl that Hyde picks up as the Veronica.
The musical Anything Goes has Hope Harcourt (Betty) and Reno Sweeney (Veronica) for Billy Crocker. Subverted in that Reno's interest in Billy is one-sided as he only has eyes for Hope. Reno eventually ends up hooking up with Hope's fiancee Evelyn Oakley, effectively Pairing The Spares.
The musical Girl Crazy (now best remembered for being Ethel Merman's stage debut as well as introducing the song I Got Rhythm) centers around a Betty And Veronica: Danny is stuck between simple mail carrier Molly (Betty, played by Ginger Rogers) and the saloon owner's glamorous daughter Kate (Veronica, played by Merman).
The musical Avenue Q has Princeton (Archie) going out with Kate Monster (Betty) before leaving her for Lucy T. Slut (Veronica). Don't worry; in the end he goes back to Kate.
The Phantom of the Opera has Christine choose between her childhood sweetheart and general Knight in Shining Armor Raoul (Betty) and the insane, brooding but more passionate Phantom. Subverted, as although Word of God says that Christine loves The Phantom the most, in the end she chooses the Safe Option, Raoul.
Romeo and Juliet: Juliet's decision between her two suitors. Paris courts her in the 'proper' way, by asking her father's permission. Romeo falls in love with her, marries her in secret and kills a beloved family member.
Depending on the production, a rare gender opposite variation occurs in Jesus Christ Superstar with Mary Magdalene (Betty) and Judas (Veronica). To the point where in the 2000 film version Judas catching Mary and Jesus in an intimate position is what drives him to betray Jesus to the authorities.
Fate/stay night: Within the whole series, this role is fulfilled primarily by Saber and Rin, with Saber as Betty and Rin as Veronica.
The series presents many other heroines which fit into this role as well. Other variants are Sakura/Rin and Sakura/Rider.
Tsukihime: Within the whole series, this role is fulfilled primarily by Arcueid and Ciel. However, it's difficult to determine which is which, because they periodically switch roles.
The series presents many other heroines which fit into this role as well. Other variants are Ciel/Akiha, Hisui/Kohaku, and others.
Analogue: A Hate Story With *Hyun-ae and *Mute. Except that, well, "Betty" *Hyun-ae did slaughter the whole population of the Mugunghwa
In If My Heart Had Wings, the twins' route is split between upbeat, sweet, but clumsy and 'average' Asa and intelligent but cynical, aloof, and sharp-tongued Yoru.
In Kissed By The Baddest Bidder, Eisuke's route has the protagonist torn between her kind, considerate supervisor Takahiro and, of course, Eisuke, the glamorous but very shady billionaire who considers her his property.
Likewise, Todd is the Veronica and Critic is the Betty to Chick.
Barbie: Life in the Dreamhouse has the goodhearted, blonde Barbie and the scheming, brunette Raquelle vying for Ken's affections. Barbie always wins. A Gender Flipped variation also occurs, in which faithful Ken competes with Ryan, Raquelle's boastful brother, for Barbie's affections. Ken always wins.
Real life Betty/Veronica tensions = brunette, cute Judy Garland vs. fast, "Sweater Girl" Lana Turner, both in love with bandleader Artie Shaw.
More famously, Debbie Reynolds (Betty) vs. Elizabeth Taylor (Veronica). After Liz was widowed suddenly, Reynolds' husband Edwin "Eddie" Fisher (father to Carrie, and the best friend of Taylor's dead husband) left his family to be with Liz. The nation sided against Eddie and Liz, until Liz came down with a near fatal case of pneumonia.
The Notorious B.I.G. and his well-known triangle with Lil Kim and Faith Evans. Which is Betty and which is Veronica is not as clear as it seems, as he and Kim were intimate for years before he met Faith.
John Lennon (Archie)/Cynthia Lennon (Betty)/Yoko Ono (Veronica, in the "exotic and edgy" sense).
Joe Jonas chose Camilla Belle (Veronica) over his Betty girlfriend Taylor Swift.
There's the famous rumor of President Kennedy cheating on his beloved wife Jackie with popular actress Marilyn Monroe. Interestingly, sophisticated, wealthy Brainy Brunette Jackie has the exotic Veronica personality while bubbly, rags-to-riches Marilyn is more of a Betty here.