The Samsung Galaxy S6 Edge
An all-in-one music player, guidebook replacement (with Triposo app), map/GPS finder, home theater and excellent camera in a pinch. It's a jack of all trades (can even crack walnuts!) but is so light it will disappear in your pocket. No more "Is that a phablet in your pocket or are you just happy to see me?" 600USD unlocked without plan
Bose Quiet Comfort 20 Noise Cancelling Headphones
Ambient noise causes stress, elevated heartbeat and exhaustion. These buds cancel out the frequency of jet engines to where you forget you are on a plane. They sound fine for music but most of the time I have them in and on without being hooked up to anything. A solid investment. 250USD
OTG Cable and a huge flash drive
Who cares anymore if your phone has a replaceable battery and a microSD card slot? With this badass little combo you can carry unlimited music and movies for those long plane/train/bus rides... and have movie night on your day off from the real world. I use a Samsung OTG cable and a Corsair 256gb thumb drive on my Samsung devices and it all works fine. 20USD/90USD
Galaxy Tab 8.4
OK, this is living large. I used to bring my Asus T-100 tablet along for long trips, and it is incredibly durable...but man is that guy heavy when everything you own is on your back. I've replaced it with a Samsung Tab S 8.4 with an OEM keyboard case... The WIFI is killer strong and WOW the AMOLED high res screen is like nothing on the market at this price and size... 300USD.