Most cafes etc buy their frites frozen, the same as in the US. Brasserie Balzar frites are quite good, made fresh. Order the poulet roti/frites dish. Also try the Belgian moule/frite spots, or any high-end steak house, like Gourmets des Ternes.
Thanks. Incidentally, Oakglen is right, frites are frozen in most places and that's often how they taste best (that's how Keller has them done in his Bouchon, eg). Not sure you'll find frites in France significantly better than the good ones in NYC.
That's good to know. Thanks. I'll stick with things like croissants and millefeuilles where a good French version is significantly better than anything you can find in NYC. Perre Herme and Jacques Genin, here we come.