Portillo's Downers Grove • 1963

Dick Portillo launched his Chicago street food empire from a humble stand called The Dog House in 1963, selling Italian beef and char-grilled hot dogs that would define a generation. This Downers Grove outpost made history in 1983 as the chain's first drive-thru, cementing the brand's fast-casual model. The chocolate cake alone—a towering, impossibly moist layer cake—has inspired cult devotion, though the wet Italian beef dipped in its own gravy remains the signature move.