I like the places that look like maybe they shouldn't be there, that they are operating just under the radar of the law. Café Indépendants. Even the name suggests a sort of lawlessness. Located in the basement of what was once the offices of a newspaper company (though the tiled floor suggests a bathhouse) it looks like the sort of place where revolutionaries would meet to hatch plans for a coup d'état.
The only natural light is filtered through two deep set hopper windows where unruly plants grow in pots. There is a tangle of plumbing pipes and electrical wires criss-crossing the ceiling, and the plastered walls are beautifully scarred with decades of neglect.
I'm not sure what happens at Café Indépendants in the evening but the lunch crowd is quiet (and attractive). This is a place I could descend into, read, write and drink - for hours. The only drawback is it appears to be in a lot of tourist guide books.