So I finally made it to the beloved glacier Berthillon on Île Saint-Louis (the smaller of Paris' two islands on the Seine)... it took me a while but it was worth waiting for, and necessitates returning to again and again...
Berthillon uses only natural base ingredients - milk, sugar, cream and eggs; flavors come from fresh sources like berries, cacao and vanilla bean. So far, I've tried the fraise des bois (wild strawberry - seasonal), chocolat and agenaise. The scoops may be small, but the intensity of the flavors make up for any lack in size. They really are heavenly.
Although there's lots of competition around the city, most consider family-owned and operated Berthillon the best ice cream around. If you can't get to the little island shop, fortunately the ice cream is widely available around Paris; just look for the famous Berthillon signage.
This year marks its 60th anniversary as an official ice cream parlor so they've created a fancy ice cream dessert named la "60". If possible when you visit, get your scoop (or two), head west along the quay towards Place Louis Aragon (at the tip of Île Saint-Louis) and enjoy the view :)
Address: 29-31 Rue Saint Louis en L'ile, 75004
Hours: Tue-Sun, 10am-8pm
Note: Cash Only, Closed mid-July through the end of August