There are some movies that don't need any help and there are some that are beyond help. Despite that, I think there are some actors who always make a movie better than it would have been. They aren't always leads, but any scene they're in is worth watching. My list would start with:
JK Simmons
Rachel McAdams
Michael B Jordan
Tilda Swinton
Jeff Daniels
Ming-Na Wen
Who are the actors you feel the same way about? Or do you disagree with the premise?
Lee Pace. He has done a lot of great tv recently, and is easily the best part of the shows he is in. I hope to see a Cillian Murphy-esque rise from excellent tv to starring in great movies.
He has been in Twilight, the Hobbit movies, and the MCU which are all huge franchices. But I hope he gets good interesting parts like his chracters in Halt amd Catch Fire, The Foundation, and the Fall.
He was (and still is) my favourite part of Foundation, especially because his character is original to the show, but his portrayal definitely adds to it.
100%! The man makes anything at least watchable. So many folks talk shit about him, but there's not a single movie he's in that isn't improved by his performance; he always knows how much Cage a film needs.
I read an interview where Cage said that he always tries to make his characters entertaining. I think he generally succeeds, but I'm not sure it always benefits the overall movies he's in.
I think it depends on the type of movie. Action or superhero? A cameo from Sam Jackson is always fun. Comedy? Will Smith, or someone like Tina Fey.
However, you're absolutely right, for any movie or show Rachel McAdams enhances it. Game Night would have been an absolute bore but she made it honestly really funny. Eurovision Song Contest: Story of Fire Saga is amazing with her and Will Farrell. She turned the turd that was True Detective from unwatchable to, well it was still a turd but she was one of the highlights of it. Oh and About Time? Just perfect, tears throughout.