Well the best in my opinion is Yubikey from Yubico. Though not the $20-$25 version which is only U2F, it is still good but not the best. The Yubikeys do more t

Well the best in my opinion is Yubikey from Yubico. Though not the $20-$25 version which is only U2F, it is still good but not the best. The Yubikeys do more than just U2F, they also support storing 32 TOTP codes, PGP keys, and other things. I like the Nano versions as I can leave them connected to my PC at all times. Recommend an NFC one that you can have on your keyring as it can then be used with your phone. In reality though almost any U2F token is all you need, and they can be purchased for about $20.