I had read about a Patisserie Taffin, but it seems to have been replaced by Marcel.
The viennoiserie here was excellent - thin and flaky layers for the croissant and the pain au chocolat were both great. I also tried a brioche de chocolat, which was generous on the chocolate chips and had a nice texture. Prices were all in the €1-1.50 range, very reasonable.
The space isn't very big but is very open and has lots of natural light.
The lady working there didn't speak English but was very friendly and offered me some samples. read more