Hugh Hefner and Crystal Harris (01 of13)
Open Image ModalPlayboy playmate Crystal Harris and Hugh Hefner were set to wed in June 2011, but Harris -- who is more than half a century younger than Hefner -- called off the nuptials just a few days before their wedding at the Playboy Mansion. The couple ended their relationship completely after the broken engagement. BUT, a year later they rekindled their romance and are set to wed on New Year's Eve 2012. (credit:PA)
Ben Affleck and Jennifer Lopez(02 of13)
Open Image ModalKiefer Sutherland and Julia Roberts(03 of13)
Open Image ModalBrad Pitt and Gwyneth Paltrow(04 of13)
Open Image ModalCarson Daly and Tara Reid(05 of13)
Open Image ModalThe "Voice" host and "American Pie" star dated for almost two years before they became engaged in 2000. They were set to have a summer wedding in 2001, but Reid got cold feet and they announced their split in July 2001. (credit:Getty)
Emilio Estevez and Demi Moore(06 of13)
Open Image ModalFellow young actors Demi Moore and Emilio Estevez were supposed to get married on December 13, 1986. Shortly before the ceremony the couple announced their decision to call everything off and remain “just friends.” The next year Demi married Bruce Willis. (credit:Getty)
Jarrett Stoll and Rachel Hunter(07 of13)
Open Image ModalRachel Hunter was dumped by her fiance Jarret Stoll just two months before their August 2009 wedding. Hunter was devastated as "everything was in place for their wedding." During the split, her rep asked the media to respect her privacy during “this extremely upsetting time.” (credit:Getty)
Marilyn Manson and Evan Rachel Wood(08 of13)
Open Image ModalManson and Wood got together in 2006, but later split in 2008. They then rekindled their romance a year later and Manson proposed while on stage at a Paris concert in Jan. 2010. Eight months later, the engagement was called off. (credit:Getty)
Alec Baldwin and Janine Turner(09 of13)
Open Image ModalAlec Baldwin and Janine Turner were engaged in 1983, when they were both in their 20s and struggling to break out into show business. When the wedding was all set to go off, Baldwin broke the engagement off and Turner was devastated. "When I met Alec, I was 20. We got engaged. It was rushed, and it didn't work," she has said. "Alec taught me a lot about my emotions, about my childhood." (credit:AP/Getty)
Jude Law and Sienna Miller(10 of13)
Open Image ModalAfter dating for two years, Miller called off their engagement in July 2005 after Law confessed to having an affair with his kids' nanny. They rekindled their romance in Dec. 2009, but split again in Feb. 2011. (credit:Getty)
Chris Klein and Katie Holmes(11 of13)
Open Image ModalBefore Tom Cruise, Katie Holmes dated fellow actor Chris Klein. They got engaged on Christmas 2003, but eventually ended their relationship in March 2005 after five years together. (credit:Getty)
Jamie Belman and Petra Nemcova(12 of13)
Open Image ModalNemcova became engaged to British actor Jamie Belman in January 2011, but it ended suddenly. "Petra Nemcova and Jamie Belman confirm their separation," Nemcova's rep confirmed. "They remain close friends and thank their families for their continued support during this time." (credit:Getty)
Lance Armstrong and Sheryl Crow(13 of13)
Open Image ModalShortly after filing for divorce from his first wife in September 2003, Lance Armstrong began dating songstress Sheryl Crow. The couple announced their engagement in September 2005, but by February 2006, they revealed they would not make the trek down the aisle. (credit:Getty)