Sutton's is a great old-fashioned drug store on Franklin Street--the kind with a lunch counter and a pharmacy.
It's super-busy at lunch time with a mix of students and professionals. It really says a lot about a place if professional businessmen are willing to brave the traffic/parking nightmares of Franklin Street for a burger and fries.
Speaking of burgers and fries, they're great at Sutton's and the price is just right.
There's sometimes a long wait for a table, but if you're alone or with just one other person, I'd suggest squeezing in at the counter, where you get very prompt service. Plus, you get to watch them make your food.