Nobody considered _____ good actors until _____

Don't know that I agree with a few of these. He obviously hadn't received awards attention but I thought Ledger was already viewed as good before then in the "promising young actor" category. So Brokeback was a breakout for him to an extent but it's not like everyone thought he sucked.

People who were paying attention absolutely already thought PSH was great. Capote isn't even his best work up to that point. Winning an Oscar will certainly increase your name ID but I wouldn't say "nobody considered him good".

Probably right on the others. At the end of Dawson's Creek most people thought Katie Holmes was going to be the one with the big movie career and Weisz was mostly just known for The Mummy. People also forget how controversial Knightley being cast in P&P was. The Austenites on the internet went nuclear.

Maybe Dean Martin before Rio Bravo.

You know my age is really exaggerated I mean, how old is the wind after all? Do people ever ask the sky how old it is? I mean those people who talk to the sky at all obviously...........um........

Jane Fonda I think fits here - she was a sex symbol until They Shoot Horses Don't They? and she courted that image as Roger Vadim's very sexy wife too - no one really thought she had those chops although in retrospect she was doing good work through the whole 60s but at the time it was more .....

 

Oscar Isaac pre-Inside Llewyn Davis (or perhaps Drive), though some of his more recent works suggests he might be returning to his "roots".

Also, though I don't think people began thinking of him as a great actor, there was a tremendous positive shift for Keanu Reeves after John Wick.

McConaughey was something of a prestige actor in the mid to late 90's. He was in things like A Time To Kill and Contact and Amistad. 

90's McConaughey was considered a very good actor indeed. He was being marketed as the new Paul Newman.The guy was scoring leads in Steven Spielberg  and Robert Zemeckis oscarbait (and they were both at the peak of their power as directors in Hollywood when they cast McConaughey).

It went a bit wrong for McConaughey. He made some poor, generic choices that didn't showcase him as an actor, and fell into becoming a lead in disposable and shallow romantic comedies, when the genre was reaching it's most formulaic nadir. So for nearly a decade McConaughey managed to make people forget that they once considered him a potentially great actor. But he was considered a pretty good actor before the McConniassance. You just have to go all the way back to that mid 90's window where all the top directors thought he was the new Paul Newman.

God, I remember when in the mid-2010s, when Oscar Isaac was sanctified as this immense, can-do-no-wrong heir apparent to Pacino that everyone on IMDb and beyond loved, and I was out there going, "Uh, did you guys not see Robin Hood or Sucker Punch?"

There were enough people who liked her pre-2013 work - like Lost in Translation and Match Point -, but I think that after Her and Under the Skin that year, there was a huge switch in how cinephiles saw Scarlett Johansson.