A block from Fenway Park, Tasty Burger serves exactly what it says. The excellent 1/3-pound burgers would be a deal anyway, and the fact that they’re made of grass-fed beef means they’re a steal. You’ll pay extra if you want more than lettuce and tomato on your patty. You can also get a terrific hot dog, crispy chicken sandwich, or turkey or veggie burger. The best side dish is onion rings, available straight up or mixed half-and-half with French fries. The Harvard Square location stays open till 4am and has a pool table, but the renovated-service-station design of the Fenway original gets me every time. At both, you’ll see students and families all day, bar- and club-hoppers in the evening.