Poilane, Pimlico, London (Galette des Rois in season)
An outpost of the well known French bakery.
Excellent classical pain au choc -- gently crispy exterior, remarkably light and puffy on the inside, with evenly distributed wisps of pastry, and a soft vein of liquid chocolate, the consistency of nutella. A textbook example of this pastry, exemplary quality, yet at £1.20, costing no more than a generic version.
Galette des Rois is in season now, delicate almond/frangipane encased in light, crisp puff pastry. Also worth getting.
I had just chanced upon the GdR when I went in for a pain au chocolat, haven't really seen it elsewhere except Paul (which if like their other stuff is probably ok). But haven't been to that many good French bakeries so far (any favourites? they seem few and far in between), but it might be worth calling The Nightingale bakery in Clapham to see if they have it.