In coordinated black outfits, Kristen Stewart and Robert Pattinson step out for the hit film's London premiere. Plus: Britney Spears, Taylor Momsen and more

ICING ON THE CAKE

After performing under the big top and announcing her tour dates, Britney Spears keeps the party going Tuesday night, celebrating her 27th birthday – and the release of her album Circus – in a slinky Roberto Cavalli gown at a party at New York hotspot Tenjune.

See how Britney turned her life around – and look back on more big moments of the year – in our Best of 2008 special!