Golden age
Bette Davis in Now, Voyager and Katharine Hepburn in Summertime.
The 1980s and 1990s
Sally Field in Norma Rae and Julia Roberts in Notting Hill.
Since 2000
Meryl Streep in Julie & Julia, Diane Keaton in The Family Stone and Reese Witherspoon in Sweet Home Alabama.
Newer names
Amy Adams in Big Eyes and Anna Kendrick in Up in the Air.