Which actors going by decades, would you say mastered their field & in which performances did they peak?

Vincent Price, and he was awesome in everything he acted in, all the way to Edward Scissorhands.

Also, Donald Pleasence, and I think he peaked in the Halloween series. He was awesome in his older flicks as a villain, (Although I saw most of those after Halloween.) but seeing him as a good guy is very…bizarre and strange, but more than well done, especially considering just how twisted his usual roles are.
He plays very well the relationship between Loomis and Myers, and just because of him that series exceeds over any other cheesy slasher franchise.

I also totally love Béatrice Dalle, but I haven’t seen enough of her movies to make a proper judgement.

opinion

@Symbeline I love Vincent Price, what a voice.My favourite Price movie has to be Theatre of Blood.Camp as christmas but nevertheless hugely enjoyable.Especially enjoy the scene where he feeds Robert Morley’s Poodle’s down his gluttoness neck, brilliant.

80’s: Sigourney Weaver in Gorillas in the Mist
70’s: Jack Nicholson in Chinatown was restrained and perfect.
60’s: Peter O’Toole in Lawrence of Arabia

To start: 80’s Meryl Streep Sophie’s Choice

I don’t think I could break it down by decade. Most of my favourite actors have been working for many, many years, and transcend decades.

Clint Eastwood, Christopher Lee, Christopher Walken, Patrick Stewart, Kevin Bacon…

Steve Mcqueen: 60’s – Papillion
Gene Kelly – 50’s Singing In The Rain
Norma Shearer – 30’s – The Women Jungle Red!

Marlon Brando – A Streetcar Named Desire
James Dean – I never saw him until the last ten years but he was great in Giant w/Liz Taylor
Not good w/names. Have to think of more….
Vivien Leigh – Scarlet O’Hara in Gone With the Wind and Streetcar, (Above)
Clark Gable – Rhett Butler in GWTW w/Leigh
Montgomery Clift – not quite as good as the others, IMO – I can’t even recall his movies!!