I highly recommend going to the WWII Museum. We just spent four days at the museum and it was excellent. The movie narrated by Tom Hanks was also excellent.
If you go: Best rate is military. If you've served, you get the rate. I recommend buying a membership if you plan to spend more than two days there. You can pay for one day then take your receipt back within the week to get a second day for $7. Two days was our original plan. But we knew within two hours that we were in for the long haul so we went back and bought the membership. However, they only applied $15 per ticket instead of the $25 we paid. This is the reason I recommend buying the membership up front. Ours is good to year end.
We stayed at Bayou Segnette State Park: Water, electric, good shower houses, free laundry, NPS senior card gets you half price, 20 minutes easy run to the museum. Parking garage next to museum is $18/full day. Restaurants a couple blocks away or two inside the museum. They also rent over water cabins looking out at the bayou that sleep eight for $150/night. I don't think you get a discount on those but they'd be great for families or groups.
Note that the PT Boat is out of the water for the season so you can't pay the $305 for a ride on her in Lake Pontchartrain (or the less expensive top deck tour)
Put this one on your bucket list. John will eventually put a blog post up on it.