Candy bars are the top pick for motorists as the best snack food for driving, according to a new survey by Insure.com. Sixteen percent chose the sweet snack for its ease of one-hand eating, with salty french fries chosen by 15%. Fries would have won but drivers complained of the lingering smell. Potato chips ranked third. Tacos were the least favorite driving snack because of messiness and lingering odor.