3. Melissa McCarthy
This one is a little obvious - but having starred with her in the new film St. Vincent, Bill Murray gave Melissa McCarthy his endorsement for the new Ghostbusters film, if it happens. She's worked with Feig before. She's worked with Murray and has his blessing, as he stated that she "would be a spectacular Ghostbuster." She's more than capable of handling comedy. The only problem is seeing how her larger-than-life persona would fit into the franchise, and into the Ghostbuster team. McCarthy has pretty much hit her saturation point, and audiences are often seeing her on screen, not the character she's playing - something that the original Ghostbusters managed to avoid despite the presence of Murray and Aykroyd.