It depends on the kind of trip you want to do. Do you want to relax? sit somewhere on a beach? see some history? experience a different culture? go on an adventure?
When our eldest was 18 months we took him to Cuba. It was nice, but there were some days we struggled to keep him entertained and DH and I didn't have a great time because we couldn't do some of the same things we really enjoyed when we had gone previous (before kids). There was only so much time we could spend in the sun, water and on the beach. We decided not to do another just beach vacation for a little while.
We did a Disney cruise a couple of years ago (kids were 9 months and 6 years). It was a lot of fun for us and them. There was always something to do for all ages, the kids could go off and do stuff on their own (9 month old could be put in the daycare), there was stuff to do as a family, and things of various levels of activity. The food was also excellent and we liked having scheduled dinner times so there was always time we all spent together. We also enjoyed being able to do stuff at the various ports of call. Infinite possibilities! We are planning on going again in a couple of years. ETA: re-reading this it sounds like we didn't spend time together, but we spent most of the trip together as a family. It was lovely to ALSO be able to let the kids do their own thing while DH and I spent quality time together and we always knew what time dinner was, so that helped us plan our time.
Then last year we went to Thailand, that was a great trip as well! Plenty of adventure and new experiences for us all. Kids were almost 2 yrs and 7.5 yrs at the time. I did a lot of planning, we didn't do an all inclusive/package (but I'm sure you could) and we spent some time in the northern, central and southern parts of the country. We went to an elephant sanctuary, a cave, hot springs, a water park, went to the night markets, toured the palace etc. There was so much.
I love planning trips but I'm more of an adventure trip person than an all-inclusive beach person. If I was given money I'd think about the places on my bucket list and go from there. Maybe pick a few places that you would like to go and then start doing some comparison pricing? If there is somewhere on the list that you'd like to hit and know you will likely not have the money to do it another time that could be a driver. Or maybe you find that there are 3 other places you can go for the same price and that outweighs the "one and done" option.
Whatever you choose I'm sure you'll have loads of fun!
