Since 1960, Mr. Bartley’s has pulled in Harvard students and Cambridge locals with its big, juicy burgers. The menu names them after celebrities, politicians, and pop-culture trends, with corny explanations (the iPhone burger, “‘Siri’ously delicious”), but only the names change. Also holding steady are the wacky vintage signs, posters, ads, and other throwback amusements that plaster the walls of the jam-packed dining room. You can decide for yourself what you want on your burger, so I’ll offer just one piece of advice: Order the onion rings. Bartley’s accepts cash only and closes on Sunday.