What is the best snack to get from those rest area vending machines?

I like Combos. You get two food groups with a little protein.

Combos + Sugar Free Rockstar is my go to gas station meal when traveling.

I regularly stop at every rest area on a trip and don't buy anything but check the coin returns. I make an average of $3 per stop which pays for part of my gas for the trip and is worth the time to stop. Always check coin returns at those places, especially at night time when people are tired and just forget about their change.

I like the little cups of coffee with the cards on the side and some donut sticks though.