If it was good enough for Jackie O. every weekend for brunch with her kids, it’s good enough for you. Some of her iconic, timeless grace must’ve rubbed off on the 1884 saloon — the original location, on Third Ave — which has nimbly detoxed the nostalgia of smoke-filled rooms and three-martini lunches without neutering itself into a glorified TGI Friday’s. The crowd reads like a costumed viewing party for a Mad Men marathon. The staff will both coax and rib you with pal-o’-mine familiarity. Its housemade corned-beef hash and “jumbo” Bloody Mary are refreshingly brawny (and hangover-friendly) takes on brunch. Its burgers are magnificent, especially those with its Wagyu-beef short-rib blend. And, while its steaks are ostensibly the stars of the menu, really this is a place for tavern-y merriment, greased in equal parts by slippery oysters, a crispy onion haystack, and tried-and-true booze. Although if you ever see waffles on the menu, order them; it’s Jackie’s recipe.