Oh man, South of the Border is a fixture on I-95. Several times our family would use the kids' spring break to drive all night from Northern VA to the Florida Keys for scuba diving trips. I vividly remember seeing the signs miles beforehand and those things would sometimes be the only thing keeping me awake (oh, and maybe an energy drink) as I drove by at 2:30 am.
South of the Border: You never Sausage a place!
That one was my favorite.