Based on the Broadway musical, which, in turn, is based on vintage ABBA tunes, the 2008 Hollywood adaptation of MAMMA MIA! features the star-studded cast performing classic tracks by the beloved Swedish pop group. While most cast members (including Amanda Seyfried and Pierce Brosnan), acquit themselves admirably, Meryl Streep truly shines on buoyant songs such as the title track and "Dancing Queen."