...is borei peri ha-adama.
This is the virtually universally-held opinion among the poskim. Actually, I couldn't find anyone who said otherwise, I'm just covering myself by using the term "virtually."
Of course, there were (mainly chassidic) poskim who held that the beracha on a potato itself is shehakol. They assumed that it was more like fungus than a vegetable, and the beracha on a fungus (like a mushroom) is shehakol, since it doesn't really grow from the ground, more like on the ground. But we don't go by that opinion regarding potatoes, we make a ha-adama on potatoes, and therefore we make ha-adama on potato chips.
Frankly it's absurd that anyone would even suggest otherwise, knowing full well what the correct beracha is, but unfortunately that's what we have to put up with regularly at The Roslyn Synagogue. And that's also why, unfortunately, no one can expect to learn halacha and how to live a Jewish life at The Roslyn Synagogue--a lot of talk about scotch, the Mets, Catholic Israel, and how all right-wing rabbis are bad, but not very much in the way of, um, you know, practical Torah observance.
