Britney Spears, Paris Hilton, Other Stars Flock to Cade Hudson's 35th Birthday Party

Britney Spears and Paris Hilton were just 2 of the famous faces who came out for one lucky guy in Hollywood -- mega-agent Cade Hudson, whose birthday was a who's-who! Several A-listers attended Cade's 35th bday party Saturday, which he hosted at…