A must lunch stop is Jess' Quick Lunch located on the square in downtown Harrisonburg. They have another location near the Valley Mall, but the downtown location is the original. The atmosphere there is like stepping back in time. I love to eat at the counter. This place could be an episode of that Diners and Dives show on the food network.
They are famous for their hot dogs, handmade burgers, and fries. It was one of our favorites when I attended JMU back in the day. Take the Rt. 33 west exit off of I-81, and it will take you right into downtown. Enjoy!
Hiya prof - Don't know if you're looking for something specific - elegant or casual, diner or ethnic, but I remember the Spring House in Woodstock was always good, although I haven't been in awhile.
In New Market there's Johnny Appleseed Restaurant and Southern Kitchens, both have decent food for a traveler.