La Maison d'Isabelle is the Latin Quarter bakery widely credited with one of the best butter croissants in Paris — it has won croissant competitions, and the queue out the door most mornings is the proof. The cooking is straightforwardly excellent rather than trend-driven: this is a place that does the fundamental thing — the croissant — better than almost anyone. For the platonic Paris breakfast, this is an address worth crossing the river for.
A Latin Quarter boulangerie celebrated for its award-winning butter croissant and classic viennoiserie.
9 Boulevard Saint-Germain. The croissant other croissants are measured against.
The croissant au beurre is the reason to come — and it has the awards to back the hype.
Expect a morning queue.
Go for breakfast; get there before the croissants run low.