Dale and I always like to talk about what being a “great” actor means. We both think that it means that you aren’t even aware that the actor was in the movie or show until you see the credits. They can change their voice, their appearance, so that they disappear into the story they are telling.
There are some actors that are “good” but you know they are there, like Robert Redford and Morgan Freeman.
People like Gary Oldman, who was Dracula, and Beethoven, and a wizard, those are “great” actors.
(Johnny Depp could be considered “great,” but he very rarely has a great movie anymore. They tend to be campy and too similar to each other. Transcendence might be the one that isn’t the same as the others.)
I would like to suggest that Christopher Heyerdahl could be considered a “great” actor.
He has been in a lot of shows that we watch, and we don’t even realize it at first. (Gotham, Sanctuary, Stargate Atlantis, Twilight to name a few.) I really enjoy watching him work. If you haven’t seen him yet, take a moment and look up his work. Enjoy!