Britney Spears has been making hits in three different decades. She was perhaps the biggest solo female star of the TRL era; more recently, she had one of the biggest pop residencies in Las Vegas. So what's left? Well, making friends with a Samsung-shilling alien. Her new video for the Iggy Azalea-featuring "Pretty Girls" is based on the 1988 Geena Davis/Jeff Goldblum musical comedy Earth Girls Are Easy, as all music videos should be. As with most of Azalea's best work, it's vaguely human. Spears' last album was 2013's Britney Jean, which featured a guest turn from T.I. on "Tik Tik Boom."