I have a killer sweet tooth and my metabolism when I was young was insane because I grew taller really fast (literally got some stretch marks from how fast I got taller), so I used to snack on junk food in general a lot. If I had to pick absolutely one favorite, it's probably either Reese's Cups or standard Cheez-Its, but there's so many runner-up snacks that are close that it's really hard to choose. Unfortunately , that also includes a lot of discontinued snack foods that didn't take off and will probably never come back. God, I miss Hershey's Gold.