Rent a house someplace I have always wanted to go. Top priority for me now would be Australia and/or New Zealand, because you just can't even scratch the surface there in a week or two. Though I'd also consider throwing the family in an RV and just going around the US - we used to live in the Rockies, but I realized my own kids have never been there, so a month going up/down/around would be awesome.
We did this a few years ago when DH got double vacation (they changed how it was earned, and he was already close to maxed out on what he could carry over, so it was take an extra-big vacation or lose it). We looked at each other and said "Europe? For a month?" I was terrified because I was busy and had never tried to take that much time off myself (and, umm, because I'm cheap), but I just went ahead and did it -- and, surprise, everyone respected my time away and didn't bother me!
I like the idea of being in one place and really being able to explore, cook at home with local ingredients, do laundry, and basically feel like you are living there. DH likes going different places. We compromised with two weeks in one place and another week and a half (total) in two other places. Still the best trip we have had since our honeymoon.
Our FIRE plans are basically the slower version of this, BTW. At least for the first however many years.