That blog is pretty clutch. Wish I could download songs past the first page though! I need French girls singing nice, upbeat songs for a "between sketches" comedy show. Thanks for all the suggestions so far. Please, by all means, keep them coming!
I second Coeur de Pirate - wonderful.
Madeleine Peyroux sings a good bit in french, although is slightly more jazz/pop.
Yelle is great fench electro-pop - Ce Je and Je Veux Te Voir are both good tracks.
I actually just stumbled upon a good one today from forkcast that I published on my own blog as well. It's a B-Side from the Swedish group Top Sound (don't worry - sung in French)