I use the Yubikey 4 nano cause I like that I can just leave it in the develop and it doesn't take extra space (except occypying a USB port).
It seems like Yubikey 4 nano is also now available for USB-C and is called Yubikey 4C nano.
It seems that the Google Titan is missing the nano format which I prefer.
https://www.yubico.com/products/compare-yubikey-4-neo/