Philippos of Greece, 25
LAID-BACK PRINCE: The London-born Georgetown grad works at a hedge fund in Manhattan-and has reportedly turned up at hipster parties. The youngest son of Greece's deposed king is, a royal expert says, "low-key and discreet."
REALITY BITES: He nixed an offer to star in a BBC reality show.
Carl Philip of Sweden, 32
PLAYBOY PRINCE: After splitting with Emma Pernald, a low-key public relations exec and his girlfriend of a decade, he came under fire for his relationship with new live-in love Sofia Hellqvist, a model who posed for photos wearing only a python.
MOVIE-STAR CHARISMA: "Everyone compares him to Orlando Bloom
," royal watcher Megan McGibney says of Philip, a race-car driver and wildlife photographer.
Joachim of Belgium, 19
NAVY MAN: Having completed officer training after battling seasickness, he didn't let military service hinder his fashion flair-showing up his first day in pink trousers.
DOUBLE DATE? His older brother Prince Amedeo is a consultant in N.Y.C.-and both want to earn their own way. Says an expert: "They're not typical European royalty."
Pierre Casiraghi of Monaco, 23
HOLLYWOOD ROYALTY: This grandson of Grace Kelly's is the image of his dad Stefano, who died in a speedboat accident when Pierre was just 3.
ALTAR-BOUND? The jet-setting playboy has dated a string of models, but has been in a serious relationship with Italian countess Beatrice Borromeo, 26, since 2008. "He was waiting," says a Monaco royal watcher, "for Albert to marry."
Harry of Wales, 26
WHAT WOMEN LOVE: That ruffle-ready hair, that devilish grin, those polo player's shoulders-what's not to like? But there's more to Will's baby bro-an Afghanistan vet and AIDS-orphans advocate-than meets the eye. Says a royal watcher: "There's a heart of gold there."
ROMANCE REPORT: Allegedly declaring himself "100 percent single" after his latest split with Chelsy Davy, he's been linked to a bevy of beauties, including lingerie model Florence Brudenell-Bruce.