I enjoy Cafe du Monde at night. Depending on when you go, there are less people and shorter lines. But more importantly, there is something about the less-crowded seating area which becomes such a wonderful setting for people watching. As it sits across Jackson Square in what would be a highly touristy area, late at night, as the tourists return to their hotels and the crowds are on Bourbon partaking in the local libations it become a more pleasurable setting in which to enjoy your beignets and cafe au lait.
Dress Code: Come as you are.
The Original Cafe Du Monde Coffee Stand was established in 1862 in the New Orleans French Market.
The reason that this is a nightlife tip is - the Cafe is open 24 hours a day, seven days a week. It closes only on Christmas Day and on the day an occasional Hurricane passes too close to New Orleans. There are 6 other locations, but this one in the French market is the only one open 24 hours. I sent one of my SILs some coffee from here for his birthday (August - before Katrina)
Hurricane Katrina gave the Cafe Du Monde a chance to upgrade the restaurant equipment and kitchens (which they couldn't do in normal operational times because it would mean closing down), and I understand they are now (October 2005) open for business again.
Beignets remind me of funnel cakes. Of course funnel cakes take a very liquid batter which is squirted into a deep fryer from a funnel. And beignets are dough which is rolled out. But both of them are sugared with powdered sugar.
Dress Code: I can't imagine that there would be any dress code. I think you could probably come in your pajamas if you wanted to.
Normally people visit Cafe Du Mode during the daylight hours, but I am listing this under NightLife for a good reason.
If you don't know, Cafe Du Mode is known for is special coffee 'cafe au lait', and dessert 'beignet'. Beignet are fried dough with crazy amounts of confectionary sugar. If you are familiar with funnel cake, it is the same type of thing. Sure they are a heart attack waiting to happen, but they taste so good. They especially taste good at about 4am after you've been out drinking all night.
This is why I am listing this as a nightlife activity.
Cafe Du Mode is one of those places on everyones 'to do' list when they get to New Orleans. People will be flocking there all day long to get a taste of the specialty dessert and coffee. But the best part about Cafe Du Monde is that it is open 24 hours a day. So, you can go in the middle of the night when hardly anyone is there. By going after hours you can turn a tourist trap into an off the beaten path place to visit. Don't go unless half the chairs are up on the tables in the outdoor cafe... that's when you know it's just the right time.
Oh, and since you'll most likely be under the influence of alcohol if you wait until 3 or 4am to go, do yourself a favor and show a bit of restraint. Beignet will taste good.....reeeeally good....but you need only eat one order. They will sit in your stomach for a bit so don't over-do it.
Dress Code: Come as you are... which at 3 or 4am will most likely be half in the bag.
I know Bourbon St. and the like are the big draws as far as nightlife goes, but I personally recommend just walking around the French Quarter and the River in the evening. It might possibly be the most peaceful and seemingly romantic place! And visit Cafe Du Monde, there's a special atmosphere at night. And since they're open 24 hours, it doesn't matter what time. But that's always what I remember most...and even just a few months ago. Of course be careful since it is a big city and all, but don't let that get in the way of having all the fun in the world! Oh and besides the French Quarter (including Bourbon St., etc) I don't really think there's so much walking around-type nightlife activities....so stick with the French Quarter!
Dress Code: No Dress Code for this...something that's comfortable I suppose! But keep the weather in mind since it can get somewhat breezy by the river!