Well, will have to go the the classics ... the golden age of cinema for the all time best actor/film personna :
Humphrey Bogart. There were/are better looking actors, there are taller actors, there are more physically agile actors. But none have his star quality. Wearing a white dinner jacket, he was billed in Casablanca 'as the most dangerous man in the world' ... sounds very familiar
! He could be funny, coldly sardonic, romantic, ruthless and altogether likeable. He could play down and out boat skippers, rich playboys, gangsters, but mostly he played Bogie. He rates above the 'Hollywood kings' such as Gable. He had the luck to have the best directors and scripts. Offscreen he was a flawed human being given to drink and surliness; but he stilll had a loveable quality that transformed to the screen.
Oh, and speaking of classics, here's another from left field : Bruce Lee. I read a famous actress (sadly, I forget her name, although she was an A-list actress who had studied with the biggie acting teachers).... anyway, she said that when she saw Bruce Lee on the screen, he was the greatest actor she had ever seen. He wasn't classically trained, but I think his secret was similar to Bogie's. He just had that something in real life that transferred to the screen; as they say, there are some people that the camera loves. I think he was a fine director, too, like Christopher Nolan, in the action genre. He understood what makes a film work. In Enter the Dragon, Robert Clouse is credited as director, but sources say that it was actually Lee who called the shots, not only in the fight scenes, but in everything. You can see the difference in other Clouse films. Lee literally gave his life energy to his films.
So there's my number one and two. Have to think about the modern era.