One way to look at the security is ; Whom have I given entrusted my private keys to? If the answer is no one but myself, then the weakest link is in yourself and no one else.

So paper wallets, Armory bitcoin signing software, (which can have paper keys as backups too) and even Bitbills http://www.bitbills.com/ are a safe way for storing the keys to your bitcoin assets.

Bitbills is based on trusting the company that has made the Bitbill and has destroyed their knowledge of the keys that are included in the cards they sell you.

Using these cold storage methods keep your coins off the internet until you want to use them.