Cape Town, South Africa: What can be sexier than hip design, pan-global food, award-stealing wine, white-sand beaches and a pre-cocktail jolt of adrenaline from a great white shark dive? Cape Town seethes with sexiness, from its funky, art-gallery-and-cafe-lined streets in gentrified inner-city hoods such as De Waterkant and Woodstock to Camps Beach, where the gorgeous gather. Start the day in your sleek bed at POD, a boutique hotel that makes you want to don a backless dress and slink through the minimalist lobby. Head to a late breakfast overlooking the water at the Grand (Camps Bay). Later, stroll hand-in-hand through the market in the Old Biscuit Mill, where you can feed each other artisanal cheeses, sample beer and shop for the sparkling wine and snacks you'll take on your gentle hike up Lions Head Mountain. For dinner, don the backless dress and make sure you're booked (six weeks in advance) at the Test Kitchen, the hottest restaurant in Cape Town. Afterward, indulge in a Nutty Slutty cocktail at the rooftop bar TjingTjing. Next morning? The shark dive, of course.
Where to set the mood: At the Planet Bar in the Mount Nelson Hotel, the historic grand dame of Cape Town, opened in 1899 and a bastion of glamour ever since.
What to wear: Silk, chiffon and sensible walking shoes
— Amanda Jones
San Francisco: If San Francisco didn't exist, Lewis Carroll would've had to invent it. Surrounded by ice water, a decrepit prison off its bow, this old city still manages a twinkle all its own. The bread is better here, and the Chardonnay takes on a different glow. Sure, the streets are hell to walk and often cold to the bone, but that only makes you appreciate the company of others. Charter a sailboat (with captain) near Fisherman's Wharf, or take in a bike ride and sunset at the Golden Gate Promenade. Finish with dinner at the elegant and renowned Fleur de Lys, where the chocolate souffle will capture your heart, even if your date doesn't.
Most romantic season: The holidays
Where to set the mood: Clock Bar, in the Westin St. Francis Hotel
What to wear: A hat and a sweater or three.
— Chris Erskine
Dishonorable mentions: Here are some other places with romantic reputations, and why they didn't quite make our list: Amsterdam (too mercenary), London (too tweedy), Hollywood (too close), St. Tropez, France (too jet-setty), Tokyo (too well-illuminated), Las Vegas (too everything).