I think it depends what you want to do. Do you want to go "yet-another-SBH-look-a-like", "yet-another-french/italian/mediterranean-place", something safe-and-easy or something totally different.
JEK's recent trip to southern Africa looked great and well within the "SBH comforts", and something similar could easily be done with a smaller budget or less organized manner. If time is right, the great migration. Botswana is the jewel but nowadays there are interesting places accessible in Zimbabwe as well. Namibia is something very different (works for animals, too), we've seen the most beautiful sunsets there. Cape region is great to add some food and wine to the trip.
Likewise there are amazing places in Argentina and Chile. We really enjoy the Chile lake district, beautiful mountains, lakes, food, thermal spa's (Termas Geometricas !), activities. Just don't expect people to speak too much english
Australia and NZ are our favourites in many ways. With Australia one has to be comfortable with great distances but the country does offer a great variety of things. In NZ one needs to get out of the cities and it's activity oriented, amazing scenery.
And if you want something really special: a trip to Antarctica. I'm all against spoiling such a fragile environment, so never leave anything on shore, don't disturb the animals, respect the continent and choose a ship that's more about the expedition than tourism.