I've recently converted to U2F security, with help from a YubiKey.
I got a yubikey from Amazon around Xmas.
On my Arch laptops, I first needed to install the
sudo pacman -S libu2f-host
I configured my GMail accounts to add the hardware token as a security device.
Now when I log in to my Google accounts I get the following.
Then it's just a matter of plugging in the YubiKey and pressing the button, which takes me straight in. My better than mucking around with SMS texts or an authenticator app on your phone (are you sure your smart-phone hasn't already been hacked?)
There aren't many sites that support YubiKey yet, but those that do are the ones you really want good security for (GMail, GitHub and Dropbox.)