Personally I've only ever found:
Jeux Descartes. 52 Rue Des Ecoles, 75505 Paris
which seems to be pretty good.
But apparently there are others:
La Guilde des Jeux
31, rue Dussoubs
75002 Paris
L'Oeuf Cube
24, rue Linné
75005 Paris
StarPlayer
3, rue Dante
75005 Paris
metro Maubert
Games in...