Israel (Tel Aviv) Morocco (Casablanca) Japan (Tokyo) U.S (New York)
The best for me would be Japan. It's safe and I haven't been there yet.
Next comes Israel. Not quite so safe, although they are doing their best to take care of terrorism.
On third place, New York. I've been there five or six times already, so that's why it's not on the top of my list. It's a nice place, though.
And I'm not that comfortable with the idea of traveling to Morocco.
It would be a matter of what experience you want and how much money you are looking to spend. Of your list, New York and Tokyo would be the most expensive places to visit.
But I have always found great deals and discounts at http://www.executivetravellink.com
Out of those 4, either Japan or the U.S.
If you guys like surfing, beaches, bikinis(:L), etc. then I'd recommend Hawaii.
Holland isnt on the list??