Phase 1 had four main competitors: three from network TV, and one from movies. They are as follows.
Portrayed by the one and only Michael Landon, Joe was the youngest of 4 single, rich, attractive ranchers in 1800s Virginia City. Unfortunately for the women in his life, NBC had a vested interest in keeping him single so that they could continue to tell love stories. In those pre-marathons, pre-binge-watching, pre-mandatory-continuity days, tragic female deaths became a routine feature of Bonanza. Joe is, quite aptly, the namesake of the Cartwright Curse Trope.
James Bond is a British spy/assassin, created by novelist Ian Fleming. He has been brought to life by no fewer than 6 actors over the course of 25 movies since 1962: Sean Connery, George Lazenby, Roger Moore, Timothy Dalton, Pierce Brosnan, and Daniel Craig. James Bond is popularly known for three things: ridiculous gadgets, ridiculous villains, and a ridiculous number of women.
Also a network-TV character from the days before season-long arcs were standard, Captain Kirk suffered from the Cartwright Curse for two reasons. First, CBS had a vested interest in keeping him single so that they could continue to tell love stories. Second, Gene Roddenberry believed free love was the way of the future, and thus included lots of plots where characters quickly fell for people who then left the picture just as quickly (either because the episode ended, or their lives did.)
Supernatural followed two brothers, Sam and Dean, who traveled the US in a 1967 Chevy Impala and fought monsters. The younger Winchester brother lost both his mother and his live-in girlfriend to a demon in the pilot, and his luck never improved by much. Unlike the other candidates, Sam was aware of, and tortured by, the fact that most of the women in his life die of unnatural causes. This is because his show adhered to strict continuity standards (enforced by rabid, mostly-female fans).