Well...now you know where my Vintage happy-place is in San Francisco. Go support them. Buy a perfect drawstring leather bucket bag for $20. Go ahead, buy a pair of decently-priced Levi's 501s that make your ass look like a peach. You deserve it.
Best vintage shop in Paris IMO? Marche Noir. Unique selection of French-meets-African style, good prices - plus, the shop is so inspiring you'll be embarrassed at how many photos you post to Instagram. Worth it, though.
Were you wondering where to find one-of-a-kind souvenirs and art objects in San Francisco? Yeah, I found it - in the Mission at Little Paper Planes. Its so good, all I can say is "shut up and take my money!"