Best Po-Boy in New Orleans PERIOD is Parran's in Metairie. Roast Beef, Oyster, Catfish... don't matter. They are still in the speed dial of my phone - when we were driving from Houston to NOLA every damn weekend for wedding planning, it was not a complete weekend without a trip to Parran's.
Best Muffalatta is Central Grocery. Hell, they invented it... I have dreams about their olive salad mix...