I use 2 factor authentication. I have the backup passwords printed out and stored behind some stuff in my wallet (probably not the best place for it, but I won't lose it there) and use my work e-mail address as my recovery address.

The work email address probably isn't a good idea if you get your work e-mail on the same phone the Google Authenticator app is installed on, or your company absolutely does not allow any personal e-mail whatsoever under any circumstance. Fortunately, neither apply to me.

I also have my landline phone number as a backup option. I'm screwed if out of town, but a lot would have to go wrong to lose access to my account. I'd have to lose my phone, lose my wallet, lose access to work VPN/e-mail, and be away from home. Very slim chance of that happening.