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We were surprised last week when Rihanna, who turned 24 today, walked the Grammys red carpet in that gorgeous black dress but she has certainly outdone herself in this silk number at the Stella McCartney Special Presentation for London Fashion Week.

She's had a few whoatown fash moments and recently we've been satisfied just to see the Barbadian beauty with pants on. Now she's officially our new style crush!

Here are some of her best and worst looks!