Rules: Actor has to be at least 30 and still hasn't broken out. The criteria for success is repeated critically and/or commercially successful TV shows or movies as lead, co lead, or major character. I would add that if an actor had a long stretch where they were rocking, they probably don't qualify. 10 years at the top is a long time in Hollywood. Make the case if you have a character actor you really like. I am re-watching Mad Men, which gave me the idea for this thread. For example, most of the Game of Thrones actors have done about what I would have expected them to do. Emelia Clarke can pull off syrupy dramas based on her looks, but is not capable of any more than that because she is not particularly talented or charismatic. Harrington's height is going to be a problem for him, and he needs to do something different than period piece badass. Maisie Williams has potential to be the biggest and longest term star of the bunch. That said, none of the cast has done particularly better or worse than you would expect given their talent, looks and subsequent movie and TV roles. I kind of feel the same way about the Mad Men cast, with an exception or two. Two examples that do fit: Mary Tyler Moore - beautiful, funny, starred in one of the biggest TV hit comedies in history, and was nominated for an Oscar. Yet she was doing cheesy TV movies and reunion shows by her late 50's, and her career was basically over by 2000. Tim Matheson - had major roles in two of the biggest movie comedy hits of all time (Fletch and Animal House), good looking, good actor, got a mid career reprieve with a recurring role on the West Wing, and he is now guest starring on middle of the pack network TV shows. Younger actors: Jessica Pare - I think she is a really good actress, as shown by a very complex role on Mad Men. Playing stupid but not too stupid is not easy, and every twist in her character's development was completely credible in a large part because of her. I think she is stunning to look at, but in a very distinctive way that makes her memorable. The huge overbite makes her more vulnerable and approachable, so she doesn't have to just play the hot babe all the time. She basically got no roles out of Mad Men, and while I haven't seen Seal Team and its ratings are solid, it doesn't look like a career maker for Pare.