Lincoln Heights has the love triangle involving Charles (Archie), with Cassie as the (Betty) and Sage as the (Veronia). Also featured was Johnny Nightingale (Bety) and Devon (Veronica) for Lizzie (Archie).
Every third episode of Ally McBeal had this plot, either for Ally or one of her clients.
Degrassi The Next Generation has a gay (male) Betty And Veronica played straight — one boyfriend is a timid neat freak, and the other one is clueless and selfish.
Later on, KC is stuck in a Love Triangle with his girlfriend Clare (prudish and low-key) and new girl Jenna (upbeat and perky).
JT had a discussion with Toby about whether he should go back to Liberty who's like oatmeal or stick with new flame Mia who's as exciting a meatball sub. Unfortunately, we never got to see how this would have played out.
The Katie/Drew/Bianca triangle fits this. Katie is the Betty to Bianca's Veronica.
Bates Motel has a textbook example, with Norman as Archie, Emma as Betty—Just Friends and openly crazy about him to no avail, as was often the case with the trope namer; and the popular, unattainable, and more conventionally sexy Bradley as Veronica, going hot and cold on him (as the original Veronica was apt to do).
South of Nowhere is unique in that it features a "Betty" and "Veronica" lesbian romance - a blonde "girl next door" who falls for her troubled, petulant, dark-haired friend - with no "Archie" in the middle, after the first few episodes.
Season 3 features an interesting dynamic. There's a triangle between Spencer, Ashley and Aiden. Which is which is unclear.
There's also Spencer with Ashley (Betty) and Carmen (Veronica)
Gilligan's Island has the perennial question of "Ginger or Mary Ann?", where Ginger is the Veronica and Mary Ann is the Betty. However, this one didn't involve an actual love triangle between the characters; it was more of a perennial debate among viewers/fans of the show, although it was also the subject of the Beauty Contest episode "Beauty Is As Beauty Does" (which threw Mrs. Howell into the mix as well).
The Original Beverly Hills 90210 had Dylan (blend of Johnny Depp and James Dean) choose between Brenda (Betty) and Kelly (Veronica). He dated both for some time, until he finally choose Kelly. Some seasons later Kelly had to choose between Dylan and Brandon (Mr. Nice Guy).
Also done a lot in the new 90210, where love triangles abound: Ethan has to choose between his on-again-off-again girlfriend Naomi and the newcomer Annie; when he chooser her, it's Annie's turn as she's torn between Ethan and her ex- from Kansas; later on, Ethan develops feelings for Rhonda (the new Betty) and finally for Erin Silver, who in turn has to choose between him and Dixon (the white WASP jock with a newfound sentimental side vs the black official boyfriend who's also the new kid in town). During the second season, it's Adrianna choosing between Teddy and Navid (the blond jock womanizer vs the Iranian-American brunet nerd with a crush on her since childhood), and later on it's Silver choosing between Teddy and Dixon (the former having become a Betty and the latter now being manipulative and Machiavellian). Liam was also Veronica in season one (with Ethan being Betty and Naomi being Archie) and became Archie in season 2 (with Naomi being Veronica and Ivy being Betty).
Willow from Buffy the Vampire Slayer was the Betty to Xander's Archie. She was a genuine love interest for Xander, but he was far more drawn, in different ways, towards two different Veronicas: Buffy and Cordelia. (This being Joss Whedon, when Xander finally started to return Willow's interest, it trashed his relationship with Cordelia, nearly trashed Willow's relationship with Oz, and did not lead to Xander and Willow living together happily ever after.)
Early seasons also have the gender-flipped version with Buffy as Archie, her friend Xander as Betty and the vampire Angel as Veronica.
Buffy and Faith had a strong Betty And Veronica vibe going, although the guy playing Archie changed regularly. Xander, Angel, Riley, Spike, and Robin all took turns - usually fairly brief - in the Archie seat. For those keeping score, Buffy was simultaneously the Veronica to Willow's Betty and the Betty to Faith's Veronica. There's probably a lesson here.
Also subverted in early seasons in that Cordelia, an obvious Veronica, was interested in a seemingly willfully oblivious Angel, who only had eyes for Betty: the "good girl" Buffy (who's actually much more physically dangerous at this point, being the Slayer and whatnot).
Willow was also Oz's Betty, as opposed to sexy werewolf Veruca. Betty wins, but then Oz leaves, realising that he's a danger to people and has to go figure out his condition before he can be around her.
In season 8, Willow's girlfriend Kennedy was her Betty, with Willow's mentor/lover Aluwyn, the snake demon lady from a magical dimension, as Veronica.
In the Season 7 episode "Him" Dawn and Buffy fall in love with the same guy due to a love spell. Dawn tries to kill herself because she doesn't think she can compete with her big sister who slays demons and has rough sex with vampires.
Gender flip version for Angel; the quiet, mysterious vampire who used to be the greatest monster the Buffyverse had ever known that Buffy falls so hard for, and Spike; the brash arrogant Foe Yay loaded sired by Angel love interest who falls so hard for Buffy that he goes to great pains to reform. The two also have an ongoing love\have relationship, and the season 9 comics addresses this.
A gender-flipped Angel example: Fred (Archie) had to choose between the tough, street-smart former gang leader Gunn (Veronica) and the bookish, nerdy Smart Guy Wes (Betty). (Ironically in Season 5 these roles are reversed, due to Wesley talking a level in badass and Gunn getting a brain implant). Eventually, she chose her Veronica, then broke up with him, turned to her Betty, died, became an ancient goddess, nearly killed both of them (one inadvertently), then Wes died. Long story.
Wesley had this vibe with his Dating Catwoman relationship with Lilah Morgan, versus his crush on Fred. Eventually he dumps Lilah for Fred, only to have his chances killed prematurely when Fred finds out about Lilah. Wes starts a brief relationship the following year, only for Fred to get killed.
Angel's complicated relationship with the noble, heroic Buffy (Betty) and Lovable Alpha Bitch Cordelia (Veronica). Which one he winds up choosing is up to interpretation.
In Dawson's Creek, Joey was at first the Betty to Dawson's Archie, while Jen was the Veronica. Later on the gender roles switched, and Dawson became the Betty to Joey's Archie, with Pacey as the Veronica.
In Teen Wolf, Scott is the Archie to Allison's Betty and Erica's Veronica, whereas in a gender swapped example, Lydia looks to be the Archie to Stiles' Betty and Jackson's Veronica.
In Veronica Mars, there's several instances of this throughout the entire series. Duncan (Betty)-Veronica-Logan (Veronica). Veronica (Veronica)-Duncan-Meg (Betty). Piz (Betty)-Veronica-Logan (Veronica). Even Wallace gets his brief moment of Love Triangulus. Weevil and a certain dead girl and their involvement in a past-tense love triangle, an example which is especially adequate for this trope.
Try not to be confused by the fact that the female lead's name is actually Veronica. The writers lampshaded the fact by having Veronica assume a different identity, using the name "Betty" as an alias when she needed to infiltrate a rival school (and claims to have come from a Riverdale High).
And ironically while as Betty she dresses preppy ala Veronica.
And all that doesn't cover the relationships of their parents. Between Celeste Kane(Veronica)/Jake Kane(Archie)/Lianne Mars(Betty), Jake Kane(Veronica)/Lianne Mars(Archie)/Keith Mars(Betty), and Lianne Mars(Veronica)/Keith Mars(Archie)/Alicia Fennel(Betty), you've got this trope everywhere in the series. Interestingly, All three of these were resolved by the single action of a 3rd party: Veronica(Mars) sending her own mother out of town to protect her father.
In Dark Shadows, the original supernatural soap opera, Friendly Neighborhood Vampire Barnabas Collins is torn between the memory of his fiancee, Josette du Pre, a Betty type, and the Veronica type (to the max) Angelique, the witch who gave him the vampire curse. At the end he gets over his torch for Josette, and avows to Angelique that he loves her. She is then killed (albeit not for very long), and Barnabas ends up with neither.
Unusually The O.C. had Cool Loser Seth end up with popular, beautiful, initially uninterested Summer (Veronica) while the seemingly kindred spirit Anna (Betty) was quickly dropped.
Chuck: For one or two episodes, Chuck has to choose between CIA Action Girl Sarah (Veronica) and sweet deli owner Lou (Betty). Later, there's a Gender Flip example when Sarah has to choose between Chuck (Betty) and her spy ex-boyfriend Bryce (Veronica).
In My So-Called Life, Brian Krakow is the love-struck, blonde boy next door (Betty). The protagonist Angela Chase (Archie) just can't see him because she's too busy lusting after bad boy Jordan Catalano (Veronica). Luckily, Brian and Jordan are Color-Coded Characters.
Given MSCL's unusual complexity (for a teen show), there was another, even more subtle one with Brian himself, with Sharon as Betty and Rayanne as Veronica. This essentially went nowhere as Sharon already has a love interest and Rayanne is a little too complicated for Brian to handle.
Far more blatant was Brian's dynamic in "Life of Brian", between the new girl Delia (Betty) and his long-held lust with Angela (Veronica). In true MSCL fashion, he ends up killing any chance of a relationship with Delia for just a whiff of a notice from Angela.
Gilmore Girls lives on this trope, with Rory playing Archie to the following Betty vs Veronica dyanmics:
Lorelai also plays Archie a few times, with her long-time, best friend Luke acting as Betty to Max, Alex, Jason and Christopher. He wins...eventually.
Grimm: Looks like Rosalee will become Monroe's Betty while Angelina is clearly his Veronica.
Given that Angelina is alive and well this may surface in future episodes.
Conversely Juliet would be the Betty and Ariel would be the Veronica to Nick.
Rosalee's ex boyfriend and Monroe are her Veronica (brooding freedom fighter) and Betty (sweet clockworker with an interest in the strange music they both love).
Nick and Renard may become this to Juliette (he had a flashback of their kiss, which may show that he is interested in her).
LOST: Jack (Betty), Sawyer (Veronica), and Kate (Archie). But in season five, it becomes: Juliet (Betty), Kate (Veronica) and Sawyer (Archie).
Gossip Girl has used this several times, most effectively with Blair having to choose between Nate (Betty) and Chuck (Veronica).
Quite ironically, during the first season, both Chuck and Nate were 50/50 Betty and Veronica: Chuck was the bad boy but was always there for Blair; Nate was the cute soulmate-type but in reality he'd cheated on her and was still in love with Serena.
Perhaps a better example (though not nearly as popular) is the way Vanessa acted as Betty for Dan, while Serena, Georgina and the Hillary Duff character were Veronica's, the latter being the one who pointed out how Dan had developed feelings for Vanessa.
Blair is the Veronica to Serena's Betty, with Nate as their Archie during Season 1. It could be argued that since Serena slept with Nate while he was dating Blair it technically makes her the floozy other woman (read: Veronica), but Blair is continuously the scheming mean girl to Serena's sunny, sweet do-gooder and their natures are constantly clashing. Plus strict adherence to color coding.
The third season of Friends has Ross choosing between Rachel (Betty) and Bonnie (Veronica). They're both blonde, but the trope still applies as Rachel was his best friend, on-again-off-again ex-girlfriend and the woman he'd been in love with since his teenage years and Bonnie was the exotic hypersexual newcomer. Subverted in an early episode where Phoebe has to choose between a bulky fireman and a sweet schoolteacher, only to find out both of them were both athletic and sensitive (i.e. not too different after all).
The second season love triangle between Ross, Rachel and Julie can also be seen as being an example of this.
Season 6 has Monica (Archie) choosing between self-doubting, long-time best friend Chandler and sophisticated, ex-boyfriend Richard. Apperance wise, its fits, as Richard is Tall, Dark and Handsome and Chandler is fairer haired and not considered very attractive. Monica still picks him.
A gay example, in an episode of Ugly Betty ("A League of Their Own"): Marc St James meets Cliff who he clicks with but asks a nameless (very hunky) model out instead, before being confronted by Cliff who was trying to ask him out.
Dexter has sensible, kind (and blonde) Rita as Betty to dark-haired, dangerous, manipulative former addict Lila as Veronica.
Interestingly, as he is a sociopathic serial killer, he'd likely be just as happy without either of them - but he needs them as cover.
The Many Loves Of Dobie Gillis had a revolving cast of pretty, money-hungry Veronicas, most notably Thalea Menninger. His constant and loving Betty was the somewhat tomboyish Zelda Gilroy.
Private Practice has also used this often, most obviously with Violet as the Betty, Charlotte as the Veronica, and Cooper as the Archie.
One Tree Hill has a similar situation among three of the main characters. Lucas(Archie) continues to flip between Peyton(Betty) and her best friend Brooke (Veronica).
Done Aborted Arc style in The Adventures of Brisco County, Jr. where the pilot introduces both the scholarly Amanda Wickwire (Betty) and saloon girl Dixie Cousins (Veronica) in what would seem to be an obvious set-up for a series love triangle. However, the chemistry between Brisco and Dixie was so immediate and obvious that the production team dropped Amanda for the rest of the series, even though her inventor father would appear throughout the series.
The BBC series of Robin Hood had (in its third season) the aristocratic Isabella as the Veronica, and peasant girl Kate as the Betty. The twist? Robin ends up with the Third-Option Love Interest; Marian, who was killed at the close of season 2 and who he is reunited with after his own death in the series finale.
On the same show, in earlier seasons, Marian had the choice between Robin and Guy, who could fit into either trope. Guy was conservative and law-abiding (Betty) but also dangerous and tortured (Veronica), whereas Robin was an outlaw and a thief (Veronica) but also Marian's childhood sweetheart (Betty).
A final example: Djaq had her choice between amoral, thieving Allan-a-Dale (Veronica) and straightlaced, sensitive Will Scarlett (Betty).
In all examples, the Betty wins.
On The West Wing, Josh Lyman's assistant Donna (Betty) falls for him, while Josh (Archie) falls for political loose cannon Amy Gardner(Veronica). However, Josh is also a clueless Genius Ditz who has no idea that Donna is in love with him and is in denial about his own feelings, so he has absolutely no reservations about courting Amy, thereby making poor Donna's plight even worse.
Victorious: Has Beck (Archie), his long-term girlfriend Jade (Betty) and the popular Tori (Veronica). Played with in that Jade is more 'dangerous' while Tori is sweet-natured. But the two years Jade and Beck have been together pushes Jade firmly into Betty territory. (Especially as Tori is an exotic new student, who everyone adores and Jade is more of a loner). Apart from a brief break up, and almost kiss with Tori, Beck remains committed to Jade and they end the series still together, happy and in love
In the early seasons of Smallville in a gender-switched version, Lana is Archie with Clark as Betty and Whitney as Veronica even though Lana didn't want Whitney because he was a great football star and couldn't seem to see just how dangerous he was.
However, this is soon overshadowed by a non-gender-switched but an unusual version, with Clark feeling attraction to both Chloe and Lana. At first glance, Chloe dresses less modestly, Lana is the literal Girl Next Doorand Chloe lost her virginity when she was 15 while Lana remains chaste before Clark, so Chloe is more like Veronica and Lana more like Betty, but after some time it is clear that it isn't that simple. Lana is often described as the prettiest girl in school (being a part-Chinese adds to the exotic bit); Chloe has the first relationship with Clark; Chloe is deeply attacted to Clark while Lana is ambiguous and more difficult to get to; Chloe/Clark is natural being Just Friends (with her often being a help to A Friend in Need, even offering advice for Clark to chase after Lana a few times before and after she admits that she likes him too), Clark (at first) only has his eyes for Lana and is completely Oblivious to Love from Chloe, Lana is the unattainable one (at first) while Chloe is dying for his attention, and so on.
From late season four to six, Chloe knows Clark's secret but Lana doesn't. Which makes it more dangerous to hang out with Lana than with Chloe in a sense. Plus Lana being attracted to and later marrying Lex and Chloe being available from the beginning till season six. In season six and seven, while Chloe is dating Jimmy, it is pretty obvious that she still has great difficulty saying no to Clark, and Lana becomes a cunning, vengeful, lying Manipulative Bitch thanks to the Luthor teachings.
Engine Sentai Go-onger seems to fit this trope, as it features Sousuke as Archie to the sweet, unspoiled Saki (Betty) and the wealthy, shallow drama queen, Miu (Veronica).
This is also Lampshaded outright by Dr. K (of all people):
"I understand your dilemma. You find Ranger Series Red attractive because he represents the guy who can give you solid security: the boy next door, trustworthy, responsible, the kind you'd take home to mother. At the same time, you're hopelessly drawn to the excitement and danger of Ranger Series Black: the tortured and mysterious bad boy you think you can save."
A double-sided version of this trope can be found in the re-imagined Battlestar Galactica. Starbuck is torn between golden boy Lee (Betty) and ex-athlete/resistance fighter Sam (Veronica), while she herself is the Veronica to Lee, with Dee as his Betty.
Dee herself has a Betty (Billy) and a Veronica (Lee Adama).
Kamen Rider Kiva gave Otoya Yuri (Betty - although more "troubled" than most examples) and Maya (Veronica) in 1986, while in the present day Mio is torn between old friend Wataru (Betty) and her foredestined husband Taiga (Veronica.) In both cases, the "Archie" figure dies.
Glee has Rachel as Betty and Quinn as Veronica to Finn's Archie.
This is subverted in the episode "Original Songs," when Quinn explains to Rachel that, however things might appear, she, Quinn, is actually the girl-next-door whom Finn will end up settling for, and Rachel is really the unattainable fantasy dream-girl.
Also Finn (Betty) and Puck (Veronica) to Quinn (Archie).
Rachel's Archie to Finn as Betty and (over the course of the series) Jesse, Puck, and Brody as Veronica.
Brittany has had a hand in quite a few of these. She was the Betty to Puck's Veronica when they both pursued Santana. She herself was the Archie when Artie (Betty) and Santana (Veronica) pursued her. She again was the Archie but with Santana as Betty when Brittany started dating Sam.
Blaine was briefly the Archie to Kurt's Betty and Sebastian's Veronica. He stayed loyal to Kurt, but never really turned down Sebastian's advances until the rock salt in the eye incident.
Artie (Betty) and Rory (Veronica) trying to woo Sugar.
Season Four has given us Ryder (Betty) and Jake (Veronica) vying for Marley. In a subversion of this trope, Marley chose Jake, even though some will argue that the two boys have better chemistry with eachother than either of them have with her.
An interesting version on the Soap OperaGeneral Hospital (a very standard Soap Opera plot, as a matter of fact), which had Jagger being torn between Karen (The Betty) and Brenda (The Veronica). However, in this case, the trope is subverted, because (a) not only is the Veronica more of a Jerk with a Heart of Gold than an outright bitch, it's she who futilely struggled to get Jagger's attention while the Betty had Jagger's undying love and devotion. Furthermore, the rebellious bad boy Jagger himself was the Veronica while Karen was undecided between him and golden boy Jason (the Betty), and this time, the trope is played straight, as Karen eventually dumped Jason for Jagger.
Dollhouse: Mellie (Betty), Paul (Archie), and Echo (Veronica). Subverted in that Mellie turns out to be a sleeper active planted by the Dollhouse.
30 Rock plays this trope straight for the second half of the fourth season with Jack (Archie) trying to choose between Nancy Donovan (Betty), a devout Irish Catholic and single mother who was his high school crush and Avery Jessup (Veronica), the fast-talking host of a political talk show who begins her relationship with Jack as a one-night-stand and whom Jack eventually chooses after learning that she is pregnant. There's even an explicit reference to this trope when Nancy doesn't think it's possible to be in love with two people at the same time, and Jack says, "It's possible. Haven't you ever read Archie comics?"
Scrubs does this quite a few times. First Dr Cox has to choose between his pregnant ex-wife Jordan (Betty), and Julia, the young, desired pharmaceutical saleswoman (Veronica). Played again when JD chooses between Elliot, one of his best friends, who needs comforting when a truck filled with her belonging is stolen (Betty) and Lisa, the pretty gift-shop girl (Veronica). And again when Elliot chooses between JD, her nerdy friend, who she's had an on-again off-again realtionship with, (Betty), and her hunky, dolphin-trainer boyfriend, Shaun (Veronica). Also, Played for Laughs Turk continually has to choose between spending time with either; JD his dorky best friend (Betty) or his wife, Carla, the sexy Latina nurse (Veronica). He always picks JD.
The Nanny is a show told from the point of view of a Veronica. Fran is the wild, lower-class "risky" option that Maxwell falls for, whereas his business partner, C.C. Babcock, is the "safe" Betty option. The Love Triangle only exists in C.C.'s mind, but that's besides the point.
C.C. herself is the Archie in a triangle with Maxwell (Betty) and Niles (Veronica). Like Maxwell, she eventually chooses the Veronica; the Betty wasn't the least bit interested, so that was probably a factor.
Torchwood has one, involving Rhys Williams as the Betty: Gwen (Archie) has to choose between Jack (Veronica) and Rhys (Betty). (Owen might also be a Veronica.) By the end of series 2, she'd chosen Rhys/Betty and during series 3 and 4 the love triangle virtually ceased to be.
The Young and the Restless has been doing this for the past few years with Nick Newman (Archie) and his current wife Phyllis (a red-haired Veronica) and his ex-wife Sharon (Betty). Athough It appears Phyllis has left Nick for good because she's tired of fighting with Sharon over him.
The Bold And The Beautiful has used this for years, most famously with Ridge Forrester (Archie), Brooke Logan (a blonde Veronica), and Taylor Hayes (a brunette Betty). Recently, the triangle has been Liam Spencer (Archie), Hope Logan (Betty), and Steffy Forrester (Veronica).
Tomica Hero Rescue Fire had Ritsuka (Archie) caught between Tatsuya (Betty) and Tsubasa (Veronica). It's left open in the finale - the boys wrestle over Tama-chan's wedding bouquet so that one of them can marry Ritsuka, but Jun rescues the flowers and gives them to her. We then see that Tsubasa is still hung up on her and carries her picture with him, but Ritsuka is very happy when Tatsuya sends a letter.
True Blood has at least one every season involving Sookie as an Archie. In Season 1 it was between Dogged Nice Guy Sam and vampire Bill where she eventually chose Bill. In season 2, it was between Bill (this time as Betty) and Manipulative Bastard Eric. Season 3 brought in Alcide to vie with Bill, and in Season 4, Alcide was up against an amnesiac Eric. In Season 5, Sookie is mostly in the background due to Anna Paquin's pregnancy, so she didn't have her usual harem fighting over her.
Male version as well in Grey's Anatomy: For a little while, Meredith (Archie) hesitates between dark haired McDreamy Derek (more of a Veronica) and the nice McVet Finn (a complete Betty).
In the teen drama The Vampire Diaries, there are quite a few love triangles. The main triangle is the one between the heroine Elena, the hero Stefan and the anti-hero Damon. Stefan and Damon are also brothers. In this scenario, Elena (Archie) is torn between her soulmate Stefan (Betty) and her unpredictable, wild friend Damon (Veronica). There's also numerous other love triangles which include Katherine (Archie), Stefan (Betty) and Damon (Veronica), Elena (Archie), Matt (Betty) and Stefan (Veronica), Stefan (Archie), Elena (Betty) and Katherine (Veronica), Stefan (Archie), Elena (Betty), and Caroline (Veronica), Caroline (Archie), Matt (Betty), and Tyler (Veronica), Caroline (Archie), Tyler (Betty), and Klaus (Veronica), Stefan (Archie), Elena (Betty), and Rebekah (Veronica), Jeremy (Archie), Bonnie (Betty), and Anna (Veronica), Bonnie (Archie), Jeremy (Betty), and Luka (Veronica), Bonnie (Archie), Jeremy (Betty), and Jamie (Veronica), Vickie (Archie), Jeremy (Betty), and Tyler (Veronica), Tatia (Archie), Elijah (Betty), and Klaus (Veronica) and the most tragic one of all, Silas (Archie), Amara (Betty) and Qetsiyah (Veronica).
In Hong Kong comedy drama To Catch The Uncatchable, female lead Vivi was torn between choosing between her sweet, handsome but dull and clueless personal trainer Jim and Detective Mok, who's snarky, smart and enjoys teasing Vivi but incredibly loyal and always helps her out in a tight spot. She lampshades to Detective Mok at one point, comparing the two to food. Jim was a plain tofu while Detective Mok was a tofu with more filling.
While it never comes up as a matter of potential relationships the character dynamic is still in full swing and played straight in That '70s Show with literal the girl-next-door Donna (Betty) and Jackie (Veronica).
Mad Men has shown instances of two such pairings. At work is the non-relationship version with simple, hardworking Peggy (Betty, or Mary Ann, if you prefer) contrasted to sultry, flirtatious Joan (Veronica, or Ginger). Outside of the office Don Draper's relationships tend to follow this pattern as well with wife Betty being cut more from the Veronica mold (cold, emotionally distant, former model) while most of Don's mistresses are typically more Betty-like.
Lost Girl has a bisexual version with female succubus Bo (Archie) having to choose between Dyson (werewolf and Veronica) and Lauren (human and Betty). That's at the start. Lines become more blurred as the season progresses
Reality TV dating shows in which a host of women try to win a man's heart will often set up the final two female candidates for the male's affections as this. Examples are Trista (Betty) and Amanda (Veronica) on the first season of The Bachelor and Paige (Betty) and Erin (Veronica) on the first season of For Love Or For Money.
The original V took this up to Evil Is Sexy levels with earnest blonde Resistance leader Julie (Faye Grant) and gerbil-swallowing brunette vamp Visitor leader Diana (Jane Badler).
Jeff as the Archie to Annie (Betty) and Britta (Veronica) in Community season 2.
Jeff himself is a Veronica to Troy's Betty where Britta (Archie) is concerned.
There's a clear example in Kyle XY with Amanda, Kyle's neighbor who's easy to talk to and plays the piano in a way that touches Kyle, compared to the heartless and ruthless Jessi.
Also Charlie is the Archie who cheats on his virginal girlfriend with the vivacious blonde and thus ends up losing both Betty and Veronica.
Switched at Birth has set this up with Daphne (Betty) declaring her feelings for Emmett (Archie), who in turn professes to only want Bay (Veronica). Complete with original trope-maker hair colours.
On Fringe, Peter was the Archie to Fauxlivia's Veronica and Olivia's Betty. Fauxlivia only became a love interest for Peter because she was pretending to be Olivia, but she was definitely the more exotic option.
On Merlin, Lancelot du Lac (aka Lancelot brought back from the dead) is the Veronica to Gwen's Archie, with Arthur as Betty.
While it never developed into an actual Love Triangle in this case, the two possible candidates for Barney's bride in the second half of season 7 qualify: This time with Robin being the Betty, and Quinn being the Veronica, the bride is Robin.
Parade's End has an interesting variant. Valentine is the Betty personality-wise and Sylvia is Veronica, but Christopher is married to Sylvia, making Valentine the "dangerous" one.
In the Series/ season 3 episode "The Boost Job" this trope is hinted at, though it's attributed to two cars. In this case, Veronica is car salesman Penzer's exotic and Betty Eliot's slightly pimped muscle car, piloted by Nate.
Penzer: "Veronica's not for sale!"
Nate: "Veronica? So Betty was the fast one. Who knew."
The first season of Mork and Mindy had Mindy (Betty) vying for Mork's affections with former high school classmate Susan (Veronica).
Early seasons of Star Trek: Voyager had Ship Tease between Tom Paris (Archie) and two female characters: the sweet, sheltered, nurturing doctor's aide Kes (Betty) and the aggressive, hot-tempered, half-Klingon chief engineer B'Elanna Torres (Veronica). The potential triangle is resolved when Kes gets Put on a Bus; shortly afterwards Tom and B'Elanna become the Official Couple.
On American Horror Story: Coven, Nan is a nice girl with Down Syndrome and Madison is a beautiful—if drug-addled—teen movie star. Both are attracted to Luke, their cute new neighbor, and welcome him in their own ways: Nan bakes him a cake (using her empathy powers to know that yellow is his favorite) and Madison shows up in a skimpy dress and aggressively flirts with him ("He's so repressed, all I have to do is say 'panties' and he'll jizz all over himself"). Interestingly, he barely even notices Madison and is instantly smitten with Nan.
Any time Frasier has more than one woman to decide between (eg Faye & Cassandra; Lana & Claire), they'll tend to have dramatically contrasting personalities which appeal to different sides of him.
The love triangle between Andy, Ann, and April in the second season of Parks and Recreation could qualify, however in this case the women exhibit traits of both the Betty and the Veronica. Personality-wise, Ann is the Betty and April is the Veronica. Ann is also Andy's ex-girlfriend (meaning he has had a history with her), while April is the snarky, apathetic, and cynical newcomer who is 8 years younger than him, making her the slightly more "dangerous" option. However, Ann is by far the more outgoing of the two and is considered by many characters to be one of the most attractive women on the show and a lot of guys have expressed an attraction to her, and while April is also very pretty, she is very much a loner. April is also the one who secretly develops feelings for Andy while he spends most of the season trying to win back Ann, who has moved on with someone else and is not the least bit interested anymore, he eventually ends up with April.
Charmed: Early season one episodes have Piper (Betty), and Phoebe (Veronica) vying for Leo's (Archie) affections, he chooses Piper.
Season two has Piper (Archie) torn between Leo (Veronica), and her new boyfriend Dan (Betty), though in this case both of them are nice guys, the reason the trope applies is that Dan is a normal guy and Leo is "The Charmed One's" whitelighter, who are forbidden from pursuing a romantic relationship with their charges, making him the more "risky" of the two options. This problem is temporarily solved when Leo has his powers taken away in the middle of the season, now human, he steps up his efforts to win Piper's affections. This forces Piper to finally make a choice between him and Dan, she ultimately realizes Leo is the one she really loves, and even after he gets his powers back, she still chooses him.