Sure New York City, Paris, Milan, and Tokyo are full of beautiful, stylish people, but in my opinion Buenos Aires has the best looking people per-capita of any city in the world. It must be the mix of the European with South American combined with impeccable fashion sense. It is in the genes of these chicos!
Buenos Aires is a city where you can afford to shop until you drop (until their economy fully recovers from the political blunders that caused its demise), but you want to be sure you return home with something unique. Something special that captures the essence of the place you visited.
My recommendation is underwear. Yes, underwear! Or I should say sexy lingerie? And the best that Argentina has to offer is Caro Cuore. To my knowledge this brand is not sold or available in the US. And Caro Cuore offers a type of "elegant South American sexy" that even the likes of La Perla and Cosabella simply cannot touch (according to my girlfriend who is the expert in this area)!