SLIDESHOW: Stage Stars Shucked by Screen Stars

7. Catherine in "Proof"

Mary-Louise Parker (pictured), best known for her lead role on Showtime’s dark comedy “Weeds,” won a Tony for her performance in the 2002 Pulitzer Prize-winning Broadway play “Proof.” Parker won a Tony Award for Best Actress for her role as Catherine, a woman struggling with the recent death of her mathematical genius father. The play was adapted for the screen three years later with Gwyneth Paltrow as Catherine, earning her a Golden Globe nomination for Best Actress. (Photo by Joan Marcus)