I use Xapo wallet, because,

1)There is no network transaction fees for transactions between two bitcoin addresses.

2)Xapo has brilliantly secured; Xapo Wallets, including Vault wallets have multi-signature.

3)It has second factor authentication code which is sent to the mobile phone associated with Xapo account via a text message to open the wallet.

4) Also, It has OTP and Pin which is verified by registered mobile to open the wallet.

So, I think this is the best wallet as per as security and transaction fees concern