I always stop into Jumbo when I'm in Vienna on business. It's basic, down home food. Nothing fancy here but nothing like fast food. You'll get a nice piece of meat (sandwich, etc.) along with a variety of sides ranging from cottage cheese to coleslaw.
My most recent entree was the chuckwagon. It is basically a country fried steak covered with brown gravy. It was delicious.
The waitresses are pleasant as well. They are more than friendly and are quick to refill your drink.
If you should find yourself in Vienna and have the means, stop into Jumbo. It's located just off the interstate. The food is good and it's fresh.