A river of red sauce once ran through northwest Denver, then known as the North Side and an enclave for Italian families that had emigrated to this country decades before. Many opened their own restaurants, specializing in the dishes of their home country — but those are disappearing fast these days. Pagliacci's closed last summer; Longo's Subway Tavern is gone; Carbone's doors are locked. But Patsy's is still going strong. In fact, this red-sauce joint that opened back in 1921 has returned to a member of the family that founded it, and you can taste that lineage in the city's best plate of spaghetti and meatball. (Yes, meatball.) The perfectly cooked pasta (gluten-free on request) is made in-house, the thick red sauce that blankets it is pungent with garlic and herbs, and that giant meatball? Fat, meaty and juicy. You're on a roll, Patsy's.