Pringles also contain corn, rice, and wheat.

https://www.pringles.com/en-us/products/pringles-the-origina...

Lay's Classic contain only potatoes, currently with a grab-bag of oils:

https://www.pepsicoproductfacts.com/Home/Product?formula=LBS...

The most "basic" mass-produced snack food award goes to: Fritos!

https://www.pepsicoproductfacts.com/Home/product?formula=LBS...

(US formulations only. Your gas station may vary.)