Hi there this page will change regularly, I will add items as they come up in my own travels
A absolute must is a good set of suitcases on wheels. Even your hand luggage, rather get a wheeled suitcase than a back pack. Your shoulders will thank me! I prefer soft to hardshell, my travels through third world airports are to thank for this nugget. This set from Amazon is perfect as it gives you many options to choose from.
Secondly a neck pillow. I am not one that easily falls asleep in a car or on a plane, but believe me when you do your neck will thank you for one of these.
After a long flight you might want to quickly freshen up in the bathroom before continuing, the same is applicable for a long road trip. For those time a set of travel sized toiletries is a must, it should be small enough to not take up valuable space and TSA compliant when your flying. This kit from Amazon as all the essentials conveniently pack for you.
When traveling to another country an adapter may be necessary, this one from Amazon is a all in one solution that can connect 5 devices, it covers 170 countries.