I tried three 'pommes frites' places in Manhattan. All of a similar (high) standard. They all use unpeeled potatoes and there are quite a few inedible 'frite-lets' in each serving.
Pommes Pommes is on Houston St between 1st and Ave A, close to Katz deli. Cheapest at $3 for a small portion. Also has non-Belgian things to eat with the fries, such as spinach and cheese pastries, but I didn't try these.
Le Frite Kot is at 148 W4th St. It is being converted into a wine bar but you can get fries in the beer bar at the back. Presented on a rack with the accompanying condiment/sauce.
Pommes Frites is on 2nd Ave between 7th and 8th streets. I had heard that this was not all that good but it seems to be OK to me...
It tastes like vegetable oil rather than beef fat is used to fry at these places. I preferred them to any I have had in Belgium, but I have only had a few samples there.