March 22, 2011 -- Hollywood has made more than half a million movies in the past 100 years, but only some have a real impact and resonate with audiences. There's no foolproof formula, but when likeable characters with chemistry collide with a timely storyline, the cinematic results can be explosive.
From Clarke Gable and Vivian Leigh in 1939's epic romance "Gone With the Wind" to Richard Gere and Julia Roberts in 1990's "Pretty Woman," select onscreen couples have sizzled and tantalized moviegoers. But out of this elite tier of films, which onscreen couples and which romantic movies are the best of all time?
ABC News and People Magazine put that question to a popular vote, asking movie fans to cast their votes for the most romantic couple of all time, the best chick flick and other movie categories as part of the "Best in Film: The Greatest Movies of all Time" special.
Over a half a million votes were cast in classic movie categories like the best line ever delivered, the greatest character of all time, best action flick, best movie musical, comedy and more. The results, including America's vote for the best movie of all time, will be revealed during the ABC News and People Magazine "Best in Film" broadcast special, Tuesday at 9 p.m. ET on ABC.
Which onscreen pairs took home the title of the most romantic of all time?
The Most Romantic Onscreen Couples
5. Spencer Tracy, Katharine Hepburn – 10%
Spencer Tracy and Katharine Hepburn, also known as Spence and Kate, first met on the set of the 1942 movie "Woman of the Year" and movie magic was born.
"They are the originals in terms of the witty repartee," said Alynda Wheat, People Magazine movie critic.
The duo starred in nine films together, including "Without Love" and "Adam's Rib," arguably their best film. Their pairing on screen became legendary -- a perfect blend of sweetness and sexiness, humor and passion.
"Spencer Tracy and Katharine Hepburn were such a great couple because they were great fighters. They didn't take any guff from each other, but yet they loved each other," said Los Angeles Times awards expert Tom O'Neil.
Their battle-of-the-sexes clash not only steamed up the silver screen but in real life as well, starting a lifelong romance between the two, although they never married.
4. Humphrey Bogart, Ingrid Bergman in "Casablanca" – 12%
Set against the backdrop of a Moroccan nightclub during World War II, Humphrey Bogart and Ingrid Bergman play former lovers, Rick Blaine and Isla Lund, in the 1942 classic "Casablanca."
"'Casablanca' is the cinematic ultimate expression of 'if you love them, let them go,'" said O'Neil. "Rick [Blaine] must choose between his romantic love of [Isla Lund], and his real love for her health and safety. Does he let her go and live or does he selfishly try to keep her?"
The Most Romantic Onscreen Couples
3. Richard Gere, Julia Roberts in "Pretty Woman" – 14%
It's the ultimate Cinderella story when Edward Lewis, a tough-as-nails businessman played by Richard Gere, hires prostitute Vivian Ward, played by Julia Roberts, for companionship during a week-long business trip to Los Angeles, and against all odds, falls in love with her.
"She's just so charming and funny and he was so dapper and urbane that it was sort of the opposites attracting. They made a great couple because she needed to loosen him up and he needed to polish her off," said Wheat. "The whole notion that we could meet someone who showers us with riches and with love is just irresistible."
2. Clark Gable, Vivien Leigh in "Gone With the Wind" – 15%
The beautiful Vivien Leigh and roguishly handsome Clark Gable are burned forever in people's memory as lovers Scarlett O'Hara and Rhett Butler from 1939's "Gone with the Wind." Their fiery kiss against a crimson sky as they escape from a burning Atlanta has become iconic.
"They're on fire. Atlanta burns, but that's not the hottest thing in the movie," said Current TV's Infomania host Brett Erlich. "It's the fact that he loves and hates her at the same time and they couldn't have anyone else but each other because they're each so impossible."
The movie also had some outrageously daring movie scenes and lines for its time, such as when Butler literally sweeps the southern belle, Scarlett, off her feet and carries her, as she struggles, upstairs to the bedroom.
1. Leonardo DiCaprio, Kate Winslet in "Titanic" -- 23%
Leonardo DiCaprio and Kate Winslet broke box office records as star-crossed lovers, Jack and Rose, in the 1997 epic romance "Titanic." Jack, a poor artist who wins a third-class ticket to America on board the Titanic, meets Rose, a high-society woman who's engaged to be married, and opens her up to a new world.
"He shows her a world outside of the kept woman that she was...and broadens her horizons," said Erlich.
From their steamy kissing scenes on the ship to their tragic goodbye in the freezing water, the couple's love is passionate and enduring.
"Leo loves Kate Winslet so much in 'Titanic' he willingly falls to his death at the end, in the icy waters, giving her the raft," said O'Neil. "These two don't just love each other. They really, really love each other through the ages...They're ghosts at the end and they still love each other even though the ship's gone down."
The two talented actors went on to star separately in many award-winning roles. Ten years later they reunited on-screen in "Revolutionary Road," but played the polar opposite -- an unhappily married suburban couple.
Watch "Best in Film: The Greatest Movies of Our Time," TONIGHT at 9/8c on ABC.