Guess who is the top pop artist of the last 20 years? Tue-09-Oct-12 10:11 Share this By Jay-Jay FeeneyRIHANNA is stoked to be announced as Billboard.com’s top pop artist of the last 20 years.She tweeted: "Billboard crowned me #1 top 40 artist of the decade just 7 years into this!!... HistoRIH."Pink was second and Britney Spears third, Kelly Clarkson fourth and Mariah carey fifth. You May Also Like Pink & Carey planning on adopting their second child Britney Spears plans to retire after Las Vegas show Check out 2013's biggest hits mashed up Become a fan of The Edge on Facebook and on Twitter .