16. Katherine Heigl
> Birth date: Nov. 24, 1978
> Earliest acting credit: That Night (1992)
> Total acting credits: 48
Television viewers know Heigl from her role as Dr. Izzie Stevens from 2005 to 2010 on the long-running series “Grey’s Anatomy.” Heigl got her start on the big screen as a young girl in the romantic drama “That Night” in 1992. Her most successful movie to date among her 48 acting credits was her star turn in the 2007 comedy “Knocked Up,” which received a 90% Freshness rating from critics on Rotten Tomatoes.
17. Reese Witherspoon
> Birth date: March 22, 1976
> Earliest acting credit: The Man in the Moon (1991)
> Total acting credits: 61
Reese Witherspoon began her acting career as a teenager with a starring role in the coming-of-age drama “The Man in the Moon,” in which she played the lovestruck 14-year-old Dani Trant. The actress has scored a number of hits since, including “Legally Blonde” (2001) and the Johnny Cash biopic “Walk the Line” (2005), for which she won an Academy Award for her role as June Carter.
18. Alyson Hannigan
> Birth date: March 24, 1974
> Earliest acting credit: Impure Thoughts (1986)
> Total acting credits: 55
Alyson Hannigan is famous for the American Pie comedies on the big screen and her role as Lily Aldrin/Jasmine in the long-running television series “How I Met Your Mother” from 2005 to 2014 and in “Buffy the Vampire Slayer” from 1997 to 2003. The first of Hannigan’s 55 acting credits was in the little-seen comedy “Impure Thoughts” in 1986.
19. Joaquin Phoenix
> Birth date: Oct. 28, 1974
> Earliest acting credit: Seven Brides for Seven Brothers (1982)
> Total acting credits: 53
Joaquin Phoenix has been in the public eye recently thanks to his starring role in “Joker.” This was only the latest in a long and fruitful acting career. Phoenix’s earliest credit was an appearance on the short-lived television series “Seven Brides for Seven Brothers” in 1982, when he was only 8 years old. He would appear on many more television programs throughout the 1980s before switching to mostly film work, including major roles in “Gladiator” (2000), “Walk the Line” (2005), and “Her” (2013).
20. Neil Patrick Harris
> Birth date: June 15, 1973
> Earliest acting credit: Clara’s Heart (1988)
> Total acting credits: 100
Neil Patrick Harris was discovered by screenwriter Mark Medoff while Harris was attending a youth drama camp. Medoff cast him in the film “Clara’s Heart” in 1988, a drama about the impact divorce has on young boy, and the housekeeper (Whoopi Goldberg) who helps him deal with the turmoil. Harris has starred in several television series since, most notably in the long-running “How I Met Your Mother” from 2005 to 2014. His movie work includes appearances in the Harold & Kumar comedies, among his 100 acting credits.