A designer with impeccable taste, Gilson Martins is one of the first to incorporate the Brazilian flag and some of Rio’s landmarks—such as Sugarloaf Mountain and Christ the Redeemer—into bags and accessories. His designs have been in some of the world’s greatest museums: You can purchase some of his pieces the next time you visit the MoMA in New York City. But the boutique in Rio—with its friendly service and the chance of glimpsing the master himself— is best.