This was an easy one... My dream vacation is really more of a lifestyle change. I would love to live abroad - in Italy. If it can't happen permanently, I'd settle for a trip long enough to immerse myself in the culture beyond the typical tourist areas.
About seven years ago we had friends who had moved to Germany that we went and stayed with for two weeks. Those two weeks changed my life. To see how fundamentally different life is in Europe has never left me. No large refrigerators to hold a week's worth of groceries because the bakery, the butcher and the grocer are all within walking distance and you buy what you will eat today and maybe tomorrow. Think of how much food you would no longer waste because the vegetables - from Costco - go bad in the crisper before you have a chance to use them! Recycling is not optional - you have a separate can for paper and one for real garbage - the stuff Americans send down the garbage disposal to be cleaned out of the water supply at the treatment plant. Most things at the grocery store come packaged in recyclable paper packaging and there is very little plastics. Those two things alone revolutionized our lives after that trip. We are recycling Nazi's and the only time I ever use the disposal is if people who don't know are over and put crap down the sink that I cannot get out.