The Billboard Music Awards kicked off on Sunday night at the MGM Grand in Las Vegas, a gathering of some of the biggest names in music and many of Hollywood’s A-list celebrities. Musical artists like Jennifer Lopez, Iggy Azalea, Gwen Stefani and Taylor Swift attended, and the audience was treated to performances by Kelly Clarkson, Kanye West and more.

The annual event wouldn’t be complete without a list of the best and worst dressed celebs. Some of our favorite artists and A-listers showed up looking stunning -- others, not so much. Check out our favorites and least favorites above.