"Pretty Woman" was the movie that made Julia Roberts. Hooting at a polo match, singing to Prince’s "Kiss" in the bathtub, unleashing her supersized laugh when Richard Gere snaps the jewelry box at her — that’s when America was introduced to its next big movie star.

The 1990 film became the highest-grossing romantic comedy ever. And Roberts earned a best actress Oscar nomination.

So it’s a good thing that Molly Ringwald turned down the role of "hooker with a heart of gold."

Not to mention Meg Ryan.

And Daryl Hannah, who believed that the plot denigrated women. (Imagine!)

It also would have been an entirely different movie if Richard Gere hadn’t played the world-weary tycoon. Would we have flocked to theaters if original pick Christopher Reeve had been offered "the condom of champions"? Or Al Pacino, who took a pass?

This week FLUFF takes a look at the bizarro world of casting ... and what might have been in the movies. ’Titanic’

The sinking ship "Titanic" was awfully buoyant at the 1997 box office, with a romantic matchup that resonated for the ages: Leonardo DiCaprio and Kate Winslet.

Director James Cameron, who tends to know what he’s doing, insisted on DiCaprio. But if the studios had had their way, Jack Dawson would have been played by the much-buzzed-about Matthew McConaughey.

Also in the running? Brace yourself: Child star Macaulay Culkin was considered for the role of Jack. The intense Christian Bale ("Batman Begins") also auditioned — but Cameron reportedly rejected him because he didn’t want two British actors playing the two American leads.

Gwyneth Paltrow was first offered the part of Rose; she turned it down. Winslet recognized a good role when she saw it, though, and pleaded to be cast. She sent Cameron notes every day from England, which said, "I’m your Rose."

Evil villain Cal — not a big believer in the "women and children first" rule — was played by the swashbuckling Billy Zane. But Rob Lowe was also considered, as was Michael Biehn, a favorite of Cameron’s who also had been cast in the "Terminator" movies.

And Kathy Bates was almost out of a job. Country legend Reba McEntire was offered the role of "the unsinkable" Molly Brown and accepted, but later found she had scheduling conflicts. ’Forrest Gump’

Can you picture Bill Murray drawling, "Mama always said, ’Life is like a box of chocolates.’ "? He was in the running (pardon the pun) for the lead role in 1994’s "Forrest Gump." Instead, it went to Tom Hanks, who won a best actor Oscar for it.

His pal Bubba was played by Mykelti Williamson, but only after it was turned down by both David Alan Grier and moody comedian David Chappelle. Chappelle admits that he figured the movie would bomb — and that he has regretted his decision ever since. ’Pirates of the Caribbean: The Curse of the Black Pearl’

Casting for this 2003 blockbuster was a musical chairs of male leads. Before Johnny Depp put his indelible imprint on the role of Capt. Jack Sparrow, the role could have gone to Michael Keaton, Jim Carrey or Christopher Walken.

Orlando Bloom made young girls swoon in the movie as swain Will Turner. But Jude Law, his buddy Ewan McGregor, Tobey Maguire, Christopher Masterson ("Malcolm in the Middle") and Christian Bale were all candidates for the part, too. ’Superman’

It’s not easy casting this superhero. In the ’70s, a less-well-known Nick Nolte was signed for the part of Superman — before that film version fell apart.

When the production for the 1978 version of "Superman" geared up, just about every actor in Hollywood was sized up for blue tights: James Caan, Burt Reynolds, Charles Bronson, Kris Kristofferson, Paul Newman, Robert Redford, Arnold Schwarzenegger and even the producer’s wife’s dentist. In the end, they went with the guy they’d hired to feed lines to actresses auditioning for Lois Lane: Christopher Reeve.

In the ’90s, another Superman project was spawned, with director Tim Burton at the helm. Anthony Hopkins was attached to play Jor-El, and Michael Keaton signed on as Batman. Superman superfan Nicolas Cage was eager to play the lead role, until this version fell apart, too. Cage settled for naming his newborn son Kal-el (Superman’s space name).

Then Brett Ratner ("Rush Hour") tried his hand at a film treatment. His picks for Superman were Josh Hartnett, Brendan Fraser and Wentworth Miller (an actor he later tapped for his TV show "Prison Break"). Johnny Depp would have played either Jor-El or Lex Luthor, but this project, too, was doomed.

At last! The script for 2006’s "Superman Returns" stuck. All that was needed was a suitable Superman, and that’s when things got complicated. Among the actors rumored to have been considered (and possibly to have turned down the role): Tom Welling (of TV’s Superman-themed "Smallville"), Paul Walker ("The Fast and the Furious"), Ian Somerhalder (of TV’s "Lost"), Jason Behr (of TV’s "Roswell"), Matthew Bomer (" The Texas Chainsaw Massacre: The Beginning"), David Boreanaz ("Angel"), James Caviezel ("The Passion of the Christ"), Henry Cavill ("Tristan + Isolde"), Jake Gyllenhaal, and Ashton Kutcher.

They went with unknown Iowan Brandon Routh — who had won a costume contest at a Halloween party in 2003, dressed as ... Superman.