If you're going to use it for travel, you probably want as many LTE bands as possible. iPhones are best for that but as a fellow Android fan I'm not going to tell you to buy an iPhone.

My vote is for a Pixel of some type. The original Pixel is past software support but can be had for under $100 if your budget is really small. I still use mine, but I wouldn't buy one today unless it was all I could afford.

Two better options are the Pixel 2 which as already mentioned can be had for $100-150 secondhand, or the Pixel 3a, which can be had for $300 new if you sign up for Google Fi (no minimum term--you have to activate it but can cancel the following day.. or you can suspend it and use it only when you travel). If you've got the budget, the 3a is probably the better choice, but the 2 is not a bad option at all.

Motorola phones are OK, but their software updates are pretty delayed. Motorola phones are regionalized, so (e.g.) you won't have all the American LTE bands on a European-market device and vice versa. How many bands you lose and how useful they are varies by device--there are some American-market phones with no European LTE bands at all and others that are only missing one of the main three (3, 7, 20) and work fine.

As for the $100ish Chinese Android phones, just don't do it. You get old Android with unknown other crap running on it, hardware that was low-end 3 years ago, etc.

ETA: for buying and selling used phones, I've had great luck with Swappa.

ETA again: the Pixel 3a also supports eSIM, which can be a great way to get cheap data when traveling.