One of my favorite street artists in Paris is Jef Aerosol. Here's a montage of Gainsbourg pochoirs that inhabit Butte aux Cailles a hood in the 13th arrondissement.
But check out Grafrank (redacted: this website was active but no longer is available, too bad. It was cool.) It's a global graffiti ranking site. Looks like Invader is more popular than Jef.
photo courtesy of web