You guys are from New Orleans - you should appreciate fine French cuisine.
For a starter, take them to the French Laundry in Napa - probably have to sell your
first born to finance the meal, though.
Generally, we do day trip to Napa. I vaguely remember having lunch at Domaine Chandon once - not bad. Mustards Grill In St. Helena is pretty good, too.
My company sponsored us on the wine train once. Not too bad - perhaps it is too touristy.
I have stayed in the bungalow at Indian Springs Resort Spa in Calistoga. They have an olympic-size hotspring-fed pool. It was very nice. Their spa is great too (mud bath, if you are into that kind of thing). However, it is summer now. Perhaps it is too hot for that kind of thing.
Perhaps, you should also consider Sonoma. It is a bit less touristy than Napa.
Do your parents bike? Perhaps that is another alternative. Biking in Napa is nice (it is very hot in summer, though).
Try this site:
http://www.fodors.com/miniguides/mgr...ur_section=ove