I tried grilled cheese sandwiches from Sonic, Shake Shack, and Five Guys. My favorite was also the least expensive.

• I tried grilled cheese sandwiches from Sonic, Shake Shack, and Five Guys.

• The sandwich from Shake Shack seemed small, and I thought the option from Five Guys was overpriced.

• Sonic's grilled cheese sandwich was my favorite for overall value.

A grilled cheese sandwich is one of the ultimate comfort foods. And although it's a simple meal to make at home, I was curious to see which fast-food restaurant made the best version of the classic sandwich.

So, I went to Sonic, Shake Shack, and Five Guys to see how their grilled cheese sandwiches stacked up against each other. Here's how it went.

Prices may vary by location.