With the caveat that James Woods might well still be a Democrat, this is a list of Republicans, not Conservatives.
I would love to think that Sarah Michelle and Freddie were the opposite pole in Hollywood marriages to Jennifer and Brad, but I fear they may be at most financial conservatives.
Freddie Prinze Jr is a legit Republican...I heard it for myself when he was on The Tonight show and the other guests were talking about Hillary and he almost YELLLED "No way I'm voting for her...I'm a Republican!" or something ot that effect. I think the Sarah Michelle Gellar thing comes from a few comments she has made about guns and the sex on Buffy that are conservative...but I don't think she has ever said anything definitive.