I had a little bit of a revelation over the last two months in Paris: Berthillion isn't the best icecream in Paris. In fact personally it doesn't even come close. Here are three places that do:
La Maison du Chocolat
Sure, not a big selection of icecream, but when you have a chocolate sorbet this good, who needs choices? And if you felt the need to veer off the path of pure unadulturated cacao, then the caramel with fleur de sel would be an excellent bet, as would the apricot with rosemary.
Icecream isn't the only reason you want to come here: the fruit tarts are pretty great too, as are the quiche. But the pistachio icecream knocks out any competitors. An iridescent green, and with little nibs of pistachio studded through the icecream, it is fabulous, rich and creamy.
I haven't had a better fruit sorbet. They also have the benefit of being pretty competitively priced at 2 euros a scoop: this may be the best deal there is in Place du Madeline. My two favourites are the strawberry and the fig, neither is too sweet and taste purely and cleanly of ripe fruit. Come here for a kick of summer.