For Cheeseburgers at Truckstops....
Nancy's at Willow Airport, California
The Ribeye, Exit 72 I-5, Chehalis, Washington
Romine's Truckstop, Morris, Illinois (Try the Hubcap....free if you can eat it!) Gross weight limitations in Robbies rule out that attempt.
For other kinds of food....
Cal's Country Cooking, Exit 108, I-40 in Oklahoma (fresh bread out of the oven)
Soulman's BBQ....Rockwall Texas just east of the lake on I-30.