I am currently living in Quincy for a summer long work contract, and while I've been here I've found that Donut and Donuts on Hancock street is my favorite stop for lunch and for a mid afternoon iced coffee. Staff is friendly, they'll remember your "usual" after a few visits (and they are super nice to the elderly clientele they seem to get). The donuts are divine! And it is also incredibly cheap: a medium iced coffee and a donut will run you less than 3 bucks (and the donuts are huge: you'll be totally full for hours). For lunch, they have a number of wonderful sandwich options. I prefer the chicken salad on a croissant. All in all, this is my favorite local spot.