Perry shines at a London appearance. Plus: Jennifer Garner, Eva & Melanie, Duchess Catherine and more

HAIR SHE IS

Selena Gomez can't decide if she wants a topknot or a braid – so she wears both! – for a Thursday appearance on The Late Show with David Letterman in N.Y.C. on Thursday.

Obsessed or hot mess? Vote on Selena's hair!