I all depends on the flavor because i also love Pringles... pizza flavor pringles are good ;D but i do eat more lays mostly because my family likes them more.
Pringles, like instant mashed potatoes, are made with potatoes and potato pieces that are unsuitable for any other purpose. They are emulsified into a batter and then glued together with who knows what. To their good, they take up a lot less space and travel better than a bag of chips.
Can't say I am big on either one but if I have to choose, then Lays all the way! There is just something "not right" about Pringles. They are just weird.
But I love these