For us, T/As and Petros just seem "nicer". More parking spaces (and wider) than most Pilots. Some of the newer Pilots are very nice inside, but still seem to suffer from a lack of parking. Flying J's are nice for the dump stations (for our porta-potty), and usually have more spaces.
Not stopped at too many Love's, but seem to be on par with the Pilots. Found several independent "gems", mostly by accident. Most are a little run down, but have "character" lacking in most of the big chains.
Our favorite may be the Petro2 in Clearwater, MN. Bakery right inside and good food at the Nelson Bros. Restaurant. Spent Thanksgiving there. Awesome turkey dinner.