Who's the best actor?

[Bengalzona]

Currently, I'd say the best actor and actress are Daniel Day Lewis and Meryl Streep (still, she has been at the top for awhile).

Of all time, including theater, I'd say Laurence Olivier.

For just the movie era, I'd say Marlon Brando (props to Paul Newman) and Meryl Streep (props to Katherine Hepburn and Ingrid Bergman).