Best Rihanna Red-Carpet Pictures

Today, Rihanna turns 24, and to celebrate the singer's birthday, we've rounded up 10 of her most memorable red-carpet looks. She's certainly taken a "no holds barred" policy when it comes to dressing to the nines; thus, we've come to expect everything from sweet glamazon to downright skin-baring vixen. Most recently, she's stunned in two silky, svelte custom Giorgio Armani gowns, one at the Grammys and one at Stella McCartney's special Fall '12 presentation during London Fashion Week. To add to the list of notable numbers, her black lace Stella McCartney dress at last year's Alexander McQueen's "Savage Beauty" Met Gala proved a daring choice, while her ruffled neon yellow Giambattista Valli gown at the 2008 BET Awards struck a seriously bright chord. We'll leave it to you to decide which of Rihanna's red-carpet ensembles is best — click through to see them all now.