Asia: Vietnam, Thailand, Cambodia and Malaysia are all really interesting and have a lot to offer and are very affordable. Singapore has a few things so it's a good to or three day trip.
Africa: Victoria Falls is amazing and you can cross off a lot of countries while there. Very close to some game drives and you can do them by boat as well which was fun. South Africa and capetown is awesome! I didn't experience any danger there but it's fun. Rwanda is cool and I loved learning about its history and seeing the Gorillas. Kenya and Tanzania are obviously the best for animals. Zanzibar and cheetah rock were cool.