I spent I spent a couple days in New Orleans painting in a neighborhood that got bashed by Katrina. There were a lot of collapsed houses still, and the spray paint marks left by FEMA. Most of the neighbors were friendly and gave me ideas of what to add to the mural. One guy bought a wad of crack the size of a baby's fist not five feet from where I was painting, and an older lady in a purple fake fur hat invited me in to see her violet and gold apartment.
Mardi Gras starts well before Mardi Gras day, with parades and debauchery starting about a week in advance. I only went to one, on a Thursday, but it was probably the coolest event I have ever seen in the United States. Mardi Gras should be on your short list.