Ah, love triangles. Without them, we'd have a lot fewer good movies.
Hollywood is, and always has been, in love with the concept of one person pursued by two suitors. The device isn't confined to any one era, genre, age group, sexual preference or even species. It also fuels a lot more movies than you might suspect.
You think "Dog Day Afternoon" was about a bank robbery? Al Pacino's Sonny Wortzik might say otherwise.
"Rebel Without a Cause" was a film about teen angst and emerging generational conflict? Right. Take a look at Sal Mineo's face in just about any scene. He wasn't admiring James Dean's jacket.
From highbrow adapted literature ("Camelot") to lowbrow comedy ("The Wedding Singer"), effective love triangles have found ways to bring conflict, tension and depth to a story and open additional layers on a character.
Love triangles don't even have to feature three humans. After all, King Kong wasn't carrying around Fay Wray, with her boyfriend in hot pursuit, in case he needed a snack later.
You can have imaginary people in love triangles ("Fight Club"). Even "Star Wars" had a love triangle, until Darth Vader had to shoot off his mouth and make Luke feel gross for kissing his sister.
The lucky, or unlucky, souls ensnared in the love triangle don't even have to be alive. That brings us to the megaselling love triangle that returns to the big screen this weekend, when the final installment of the "Twilight" series, "Breaking Dawn -- Part 2," opens in theaters. Even though our heroine, Bella (Kristen Stewart), has technically picked her suitor, the dreamy vampire Edward (Robert Pattinson), her friend and emotional rock Jacob (Taylor Lautner) looms, and the Team Edward/Team Jacob debate goes on. Plus, all bets were off when Bella had that affair with the "Snow White" director -- oh, wait, that was real life, wasn't it?
So how does "Twilight" stack up in the history of love triangles? There's a lot to mull over, especially when you consider it's a long history. Here are some of the most potent ones.
Toward the end of its run, the Harry Potter series fit in this category. It was a given that Hermione (Emma Watson) would end up with Ron (Rupert Grint), but wasn't it a bit weird that Harry (Daniel Radcliffe) ended up with Ron's sister, who looks a lot like Ron? "Spider-Man" would be worth a mention here, but some of us will never get over Tobey Maguire playing Spider-Man. Ever.
"Something's Gotta Give" was the other way around. Sixty-something Harry Sanborn (Jack Nicholson) meets Erica (Diane Keaton) when he's in the Hamptons with his girlfriend, Erica's daughter Marin (Amanda Peet). He has a heart attack, falls in love with Erica, who starts dating Keanu Reeves. Yeah, the only way this would have been more absurd is if Nicholson had turned into a bat at the end.
In "Sabrina," Bogart just can't leave well enough alone, swooping in to steal his brother's (William Holden) girl (Audrey Hepburn). Well, not really. His brother had it coming.
"The Princess Bride" gives us the most clear-cut case of who should win in a love triangle in movie history. That's when the sniveling Prince Humperdink (Chris Sarandon), runs away from a sword fight with the noble Westley (Cary Elwes). Freud would have a field day with that one.
"The Girl With the Dragon Tattoo" was a good story, but the "love" part of the love triangle wasn't exactly cuddly. Vampires are warmer.
Then there's "Pretty in Pink." Who doesn't love watching Molly Ringwald agonizing over potential love? Even if she picked the rich guy (Andrew McCarthy) over her best friend (Jon Cryer), this was one of the best five or six teen movies of the '80s.
Then again, I was in high school during the '80s. In 25 years, someone who's a teen now might be saying the same thing about "Twilight."
To see a slideshow and vote for favorite love triangle movie, go to www.mercurynews.com/entertainment.