According to designers and menswear experts, American prep is ready for a revival—especially after so many of us have been living in sweats lately. And it appears it's starting with the humble polo shirt. The legendary shirt was all but ignored for a while but, as all things in fashion do, the "casual Friday" favorite has come back around. But this time, the polo is a little more relaxed, a little cooler. This also makes it a hell of a lot more versatile. And while they remain understated, these shirts are anything but simple. Vintage details, saturated garment-dyed fabrics that have been knit with silk or washed for softness, plus a few unusual patterns set them apart from the crowd. After all, it's hard to fault a shirt that's worked for everyone from JFK to Obama and Elvis to Pharrell. Herewith, a dozen options to suit your tastes (and budget).