Who do you think of when I say "biggest movie star of all time"?

Cary Grant. The quintessence of “movie star.”

Move-star handsome. Movie star magnetic. Movie Star charisma.

Not a particularly broad-ranging actor, not a master of disguise, not able to modulate his voice or accent very well, but always the reason people came into the theater to see one of his films, the worst of which is watchable if only to see him in it.

Okay, serious guess on my part: Jackie Chan?

Cary Grant was the first that came to mind.

Cary Grant as well.

There may have been greater actors, but there were no greater movie stars.

Gary Cooper.

Rober De Niro.
Failing which, Sean penn

Marilyn Monroe.

Names that popped into my head, in order of poppage:

John Wayne
Cary Grant
Clark Gable
James Stewart
Marilyn Monroe

Marilyn Monroe

Errol Flynn

Honestly, there wasn’t one name that popped into my head but after thinking about it I’m going with John Wayne.

My pick would be Jack Nicholson.

Clark Gable

My first thought.

Note how the only female named is Marilyn Monroe. WTF happened to Streep and Steisand?

Clark Gable was the first to come to mind. I then thought of Charles Chaplin. He was truly international.

Actually, my first thought was Liz Taylor.

Gene Hackman. I read somewhere that he was considered the most respected living actor.

But respected does not translate into biggest. Dustin Hoffman could have an equal claim.

True. Some ppl also consider the lifestyle, glamor, all that, and AFAIK someone like Hackman doesn’t command attention in that way. Or you could look at it from a “body of work” perspective: how many films did Marilyn Monroe make and how good was she in them?

Interesting trivia from imdb.com

Dustin Hoffman came to New York after finishing his training at the Pasadena Playhouse. The two of them roomed together in New York at Hackman’s one-bedroom apartment on 2nd Ave. & 26th St. Hoffman slept on the kitchen floor. Originally, Hackman had offered to let him stay a few nights, but Hoffman would not leave. Hackman had to take him out to look for his own apartment.

As roommates, Dustin Hoffman and Hackman would often go to the apartment rooftop and play the drums. Hoffman played the bongo drums while Hackman played the conga drums. They did it out of their love for Marlon Brando, who they had heard played music in clubs. They wanted to be like Brando and were big fans of his.

Dustin Hoffman asked for the part of Rankin Fitch in Runaway Jury (2003), which had gone to Hackman. Hoffman admits to asking, “Can’t you get rid of Gene and give me the part?”.

Some possibilities who I don’t think have been mentioned:
Liz Taylor
Shirley Temple

Alan Swann