I'm super interested in the flavors from other countries and what kind cultural elements influence them. Where are the best places to look for one shots?
There are lots of great options from Chef's flavours, in fact I find the amount of choice a little overwhelming. They have their own brand one-shots, along with some "guest" one-shots.
My advice would be to go to their community facebook group (the kitchen) and explain your flavour preference and then people will make suggestions for you!
Lots of the one-shots there are inspired by UK desserts, think heavy custards, bakery flavours, etc...
Most online vape shops in Europe have concentrates from all over the world, and I would be surprised if US vape shops only sell concentrates from the US. If you find international products in US vape shops you probably save quite a bit on shipping. So I would recommend you investigate where different brands are from, and see if you can find it locally.
Here are some non US brands of one-shots that I have vaped. There are tons of others. A simple search by brand name will usually help to find out where a brand is from.
Chefs Flavours (UK) Divine Shots (UK) Drip Hacks (UK) Empire Brew (Malaysia) Horny Flava (Malaysia) IVG (UK) Juice Artisan (UK) Molinberry (Poland) - they are mostly known as a single flavour brand, but they have a range of one-shots as well, some are very good Rude Oil (UK) Shot Concentrate (Poland) Vampire Vape (UK) Urban Cloudz (UK) T-Juice (UK) Steamer Elixir (Norway) Nasty Juice (Malaysia) Halcyon Haze (UK) Elegans (Norway) Crafted Liquid (Denmark) Aròmes et Liquides (France) 7sense (UK) Fcukin' Flava (Malaysia)
What's best is a matter of taste. Most brands have a wide range of flavours, some good, some bad.