Jennifer Lopez

The Latin-pop megastar turned Aerican Idol judge headlines what promises to be a dazzling sweatfest. Though J. Lo has recently gone the chart-topping, bass-bumping, party-rapping way by pairing with Pitbull, it's the older stuff that gets us going. We can't deny it — sultry dance numbers like "If You Had My Love" and "Waiting for Tonight" sound just as good as they did in 1999.