When in doubt, take a recommendation from some of the regulars.
The chicken salad sandwich is to die for. Well, maybe not actually, really, die for... but I'd drive there and pay full price for it.
Other reviewers are right -- this place is a bit pricey if you are on a budget -- but the way to get around that is to go for the daily special. For right around $6 you are out the door with your huge sandwich; a choice of chips, potato salad or coleslaw; and a drink. $1.50 buys you a giant chocolate chip cookie for dessert.
The other secret is that they sell their bread (if they have any left) after 2 pm. I'm still waiting to get a loaf of their sourdough to make into french toast on the weekend.