I have good friends who will go to virtually any movie with Johnny Depp or Helen Mirren. Other friends who wouldn't miss a movie directed by Scorsese. One or two who never miss a romantic comedy. And there's those (a lot of them!) who like movies about causes, injustices, third world suffering.
With me, it's the critical word. If a movie gets good reviews, I will see it regardless of the subject, director, stars. I can never be convinced that if a movie scores over 85% on rotten tomatoes, I might not like it.
What's your Achilles' Heel? What takes you into a theater or onto netflix most of the time?