34. Olivia Newton-John
Band Or Solo Artist?: Solo
Genre: Pop, Country
Greatest Hit: "I Honestly Love You" (1974)
Besides winning over the world as Sandy in Grease, Olivia Newton-John was one of the top female artists during the '80s, raking in four Grammy awards, five No. 1 and 10 other Top Ten Billboard Hot 100 singles. But what's most beautiful about her is her strength and dedication to humanitarian causes. As a survivor of breast cancer, Newton-John is now an advocate for health awareness, as well as environmental and animal rights issues.