I will be giving several keynotes and workshops at an upcoming conference. I have been asked by the host to have my presentations on a thumb drive so they can copy them to their systems if necessary–I suspect Windows machines but I have not asked.
I’ve got one of the Sandisk ones: https://www.amazon.co.uk/SanDisk-Ultra-Type-C-Flash-Drive/dp/B01EZ0X3L8/. It has a little slider, push it one way you get a USB-C connector or USB-A the other way.
It’s not had a ton of use so far though has been great for moving files between machines with and without USB-C.
I have the same type of drive as @stu_w. So far I have been very happy with it. I formatted it as an exFAT drive on my Mac and have used it in my iPad Pro, Windows 10 machine at work as well as my Mac.
That one has been my favourite - I like the all metal body, no need for little string to attach to keychain, or plastic parts to break in your pocket.
Format it exFat for compatibility for Mac OS (10.6.5+) and Windows (later XP) versions. If you KNOW you will only use on Macs you can format it a MacOS way.
Sadly it’s not so elegant for use with USB-C - my MacBook Pro has a little dock so I always have USB-A ports.