Katharine Hepburn - by a long long shot. Katharine Hepburn was a skilled, talented, smart actress who played serious dramatic roles and comedic roles. She was versatile and a very commanding presence on screen. She was considered the greatest actress until Meryl Streep came along - I'd place them both at the top, but Hepburn holds the lead. She won 4 Oscars, all for Best Actress, and that's the all-time record for both male and female actors. Lauren Bacall is a great screen presence, she did win one Oscar. Bacall has a more narrow range as a performer, her best performances are dramatic roles, and I don't recall her doing a comedy role except for Designing Woman and well, she didn't play comedy in my book.