Brittany
In the northwest of France, Brittany has some ties with Britain (in fact, it gets its name due to Celtic settlers, whose Welsh-like language is still spoken in some areas) and a wild coastline. It has ancient archeological sites, beautiful nature, and some excellent food—especially crepes, oysters, and various things made from dairy (especially butter), salt, and apples, which are believed to be the best in France (and thus perhaps the world!).
Eastern Brittany (Ille-et-Vilaine)
...is technically in Normandy, but it's right on the border. See the Normandy Page for more.
Cancale
***Epices Roellinger - interesting spice shop run by Olivier Roellinger (who used to run a 3-star Michelin restaurant)...they have amazing spices from all around the world; also branches in Saint Malo and Paris
***Grain de Vanille - pastry shop known for its out-of-this-world millefeuille, but also makes a lot of other yummy stuff (including the best shortbread cookies I've ever had)
***Breizh Cafe - amazing crepes, the "home base" for a small chain (in Paris, Brittany, and Japan)...they also have a fancy Japanese restaurant (La Table de Breizh) in town
halfway between Cancale and Sant Malo there is a farm you can visit and have a rustic meal at (apparently? they seem to be closed?) in Saint-Coulomb
***Le Coquillage/Maisons de Bricourt - a two-star Michelin restaurant (run by Olivier's son, Hugo) just south of Cancale, overlooking the Bay of Mont Saint Michel. Most of their dishes highlight local seafood and Olivier's creative spice blends...but the standout is the amazing cheese & dessert trays (save room for them!). They also have a cooking school called Le Corsair.
Hotel/Lodging: Château Richeux, Les Rimains, or Gîtes Marins (each with different lodging options); their Ferme du Vent "kled" rooms also gain you access to their "Celtic Baths" spa and meals (from Le Coquillage's menu) in your room (both for an additional fee)—a great option if you want to enjoy 2-star meals in privacy. All of these lodgings come with an amazing breakfast that is delivered to your room, with the best butter/hot chocolate/crepes/etc.
? Le Bistrot de Cancale - a more casual place run by Roellinger in Cancale; we didn't go there but it looks nice
Oysters
especially the flat "belon" oysters are famous in this area
at the port you can buy oysters from stands most of the day
Saint-Malo
A beautiful walled city on an island peninsula connected by a bridge, St Malo has a bunch of cool shops and food. If you've got small kids, there's a nice playground in the northwest corner of the walled city ("Aire de Jeux de l'Intra Muros").
***Beurre Bordier / Bistro Auteur de Beurre - Jean-Yves Bordier is thought to make some of the best butter in France. At Bistro Auteur de Beurre, you can try a bunch of his butters—not just the salted butter that tastes like a rich cheese, but also with interesting additions like seaweed and espelette peppers. Each of the dishes also highlights the butter—my favorite were amazingly rich escargots. (You can buy his butter at shops throughout the region, and in Paris, but the Bistro is only in St Malo.)
?Cargo Culte - looks like a cool place to eat, casual
La Maison Du Sarrasin - nice buckwheat-centric store run by the Breizh Cafe folks
?Pâtisserie Chocolaterie Philippe Bouvier - MOF for chocolate/pastries (also some branches in Rennes)
...there are also some branches of Breizh Cafe in town (see Cancale, above, for more)
Dinard
fancy seaside resort town across the bay from Saint-Malo
? Crêperie Chez le Sarrazin - looks nice
Rennes
Capital of Brittany and a bit of a college town, Rennes is the most populous town in Brittany. It features half-timbered buildings in its historic center near the cathedral, museums, parks (especially Parc du Thabor), and a big Saturday market at Place des Lices.
Simonneaux Mathilde / Ferme de la Rocheraie - on the outskirts of Rennes, this biodynamic farm produces the best apple juice we've ever had...we didn't get a chance to visit but we had their juice at the Maisons de Bricourt
Brocéliande Gardens - also on the outskirts of Rennes, this is a bit of a cross between a giant playground and a theme park, with lots of activities for young kids; somewhat expensive entry fee
Southern Brittany (Morbihan)
Guérande
(Technically in the "Pays de la Loire" region, not Brittany, but it's close to Morbihan & was historically part of Brittany.) Home to what many think is the best salt in the world, Guérande is famous especially for its "fleur de sel". All of its salt is painstakingly hand-harvested in mudflat ponds (which are also maintained by hand) that date back thousands of years old.
Terre de Sel - (their English page doesn't have much information) cool museum/shop where you can learn how the salt is made (their video was very informative), and if you reserve in advance you can take tours (including ones that are designed for small children, Adam loved the "salt fairy")
...also a great place to buy fleur de sel in bulk
Crêperie Fleur de Sel - nice crepe place south of the salt fields in Batz-sur-Mer
Standing Stones/Prehistoric Sites
Brittany (especially the Morbihan) has a number of Stonehenge-esque standing stones (called "menhirs" in Breton) and other prehistoric sites (like "tumulus" or grave mound).
Alignements de Carnac - the most famous site, with a nice museum but which controls access to the stones themselves with overly-long tours (except in winter)...if we had it to do over again, we'd probably just visit the museum and then head to nearby Kerzerho (below). Nearby Tumulus Saint-Michel is a nice walk/view but not much to see.
Chez Auguste Créperie - nice, not-too-expensive crepe place nearby, friendly service, good with kids
?Côté Cuisine - haute cusine place nearby
?Restaurant La Cote Carnac - another somewhat fancy place nearby, rec'd Lonely Planet
?Alrégal - in nearby Auray, this organic counter-service spot gets great Google reviews, could be nice for a short/quick lunch?
Alignements de Kerzérho - our favorite spot...there's a small parking lot and then you can explore a number of standing stones; also check out the nearby Menhirs Guérisseurs
Vannes
The local capital of Morbihan has a nice, medieval center; good "home base" for the region (including if you want to go to the islands, which we didn't...)
Crêperie Saint-Guenhaël - nice crepe place with high-quality ingredients and food, great for families (pretty casual), next to the cathedral
? L'EntreChoc - looked nice
? Restaurant La Tête en l'air - one of the fancier restaurants in town
Marché de Vannes - nice covered market
Le Bistrot de Jeanne - pretty good mid-level restaurant, nice food & relatively casual atmosphere
Quiberon
A resort town on a peninsula south of Carnac
?? Ty Rétro - creperie that looks good, great reviews on Google/TA (at one point was the best-reviewed creperie in all of France on TripAdvisor!), uses organic flour
? Le Poulpiquet - another nice creperie?
La Maison d'Armorine / Les Niniches - old school candy store, caramels rec'd by NYT
Maison Le Roux Chocolatier & Caramélier - fancy chocolates & caramels, rec'd David Lebovitz and NYT
...we didn't visit the islands but there are some places like Belle-Île-en-Mer that you can get to via ferry that are supposed to be nice.
Elsewhere in Morbihan
Lorient: Le Poulpe Lorient - looks like a really nice restaurant, fresh/market-driven
North Central Brittany (Côtes d'Armor)
We didn't travel much here, but here are some things on our list:
Dinan
Very close to Saint Malo / Cancale area, this cut medieval town is on everyone's list of favorite places to visit.
Côte de Granit Rose
This "pink granite coast" is known for being very pretty, especially the area near Ploumanac'h (north of Lannion).
Saint-Brieuc
Capital of Côtes d'Armor and one of the larger towns on the northern coast.
?Crêperie des Promenades - looks nice, mostly organic ingredients
?La Passerelle - a bit outside of town, looks nice, a bit fancy?
?Esprit de Famille - super-kid friendly lunch spot
?BRUT le restaurant - looks nice, a bit fancy?
?Le Koadenn - hole-in-the-wall creperie/steak place, looks cute
Western Brittany (Finistere)
Quimper
Town on the southern side of Finistere (and the department capital), known for being the birthplace of kouign amann, with a medieval core.
Pains & Kouign Guéguen - known for somewhat innovative breads & kouign amann
Douarnenez
Town not far from Quimper on the coast, known for great baked goods and historically a sardine canning center.
Boulangerie Des Plomarc'h - looks nice! Baker Lucas Thierry is known for making some really good stuff, on many people's list of "best kouign amann"
Parc d’Amorique
Between Brest and Quimper, a large, beautiful park. Pointe de Pen-Hir on the tip of the westernmost peninsula is known for its views.