We have told our kids that when they graduate from High School, they can pick a trip anywhere. The one limitation is that due to work, it is difficult for me to take much more than a week off.
Our oldest daughter picked a Caribbean Cruise. It was a great family trip. Fantastic to spend all of that time with my family.
My youngest daughter is due for a trip next spring and is having a hard time deciding. She talked about New Zealand, but with travel time, I don't think that is really practical. I would love to do one of those African Safaris, but again, with travel time, that is probably better for when I am retired and have more time...I may suggest Hawaii because I think she would really like that. She also talked about doing some kind of Disney park trip, so that is one of the possibilities. She loved the cruise and may also decide on that.
Any ideas that you have done as a family that would take about a week? No little kid limitations - we have none.