Coinbase is our first choice for a wallet, being secure, easy, mobile and cheap. You can link any US bank account to buy or sell Bitcoins, and they only charge 1% when you exchange money into or out of Bitcoin. All Bitcoin to Bitcoin transactions are free!
This cloud based wallet can be accessed on any computer or Smartphone. It is the safest way to store Bitcoins. Coinbase.com safely holds the bulk of its actual coins securely offline. Only a small amount necessary to run transactions are available for trade online, just like real currency in real bank. This is at least as safe as trying to move and store the coins yourself offline and far easier.
We use the Authy two factor authentication option which ensures security. If you leave a Smartphone logged in, and someone steals your phone, your coins can be instantly stolen, so we be sure to log off any of our Coinbase access devices when not in use.