U2F Keys from Yubico I think having this type of security (U2F Key) and replacing other methods is just excellent. Combined with a password manager like Dashlane for example is just top notch and definitely safe from attacks. It's an open authentication standard that enables internet users to securely access any number of online services with one single security key instantly and with no drivers or client software needed. They come in many sizes fit to the users needs, obviously make sure to have a few spare.

Using Yubikey introduces the risk of the rightful owner of account is prevented access. It is a problem that Yubikeys cannot be duplicated for backup. They are so secure that even the owner of an account can be locked out, lol. That's not good. In case of lost key or hardware malfunction there is no way to access your account. Unfortunatly two different keys often cannot be registered for the same access. Using Yubikey introduces the risk of the rightful owner of account is prevented access.

series 5 nfc buggy bought 2 series 5 nfc totally buggy to a point where yubikey-manager couldn’t read the seriol# of both keys anymore and AOL rejected both keys in that condition. support totally ignored my issues and closed my tickets before solving them How does anyone trust a company or a piece of hardware that buggy??

Solid 2FA I have been using the YubiKey for over 2 years now and it has saved me and my company from potential damage on multiple occasions. Just make sure to never lose your key ;)

UK customers - Beware the artificially high shipping fee I placed an order with Yubico. They charged EUR15 for shipping. My order was delivered by Royal Mail Tracked 24 service. According to the Royal Mail website, this cost Yubico GBP3.30 for an 80g shipment weight as declared on the Royal Mail label. This means Yubico have charged an artificially inflated price for shipping (GBP3.30 is EUR3.75, which is substancially less than EUR15)