If you are willing to invest, trezor or ledgerwallet nano S. If you are storing over 0.2 btc, you might want to look onto hardware wallets because probably they are your besr bet regarding safety. Of course you should generate the seeds for example ledgeewallet on a computer that is disconnected from the internet.
Trezor over Mycelium rooted through TOR orbot seems like a solid option. Can't see anything beating that for privacy and security.
Yeah maybe not on mobile, i have never had a trezor tho is it any good? I currently only own ledger wallet nano, and i have owned it for a year or so.
Works pretty well, it is cheap and easy to use over USB OTG cable. Also the positive thing is that you can verify transactions with your phone (does not work all the times tho).
I can heavily recommend it.
Even the online wallets are safe like blockchain and coinbase cause that is the most secure and trusted online wallets. They change the bitcoin address if you receive a bitcoin so its hard to detect or scammed by hackers who wants to steal your money. Also the paper wallets safety it is also have a chance to lose your money even if you save it to your sd card then the sd card has lost also your money will lost so its almost the same for me.
I think as of now the safest wallet now is blockchain because. It can change the bitcoin address it helpful to not detect or scammed by the hackers who wants to get your bitcoin. As of now coinbase have many issues because this wallet people said after transfer to coinbase did not arrived bitcoin in wallet and its already confirmed txid. One case also person bought 1 btc to coinbase but did not arrived in his wallet. My all bitcoin in coinbase was transferred yesterday to blockchain . I want to recover issue in coinbase before I transfer again my bitcoin to this wallet.
I think that using web wallets generally is a bad idea (even if you are holding your own keys). Does blockchain have access to your private keys? If answer to this is yes, it is not safe.
I have no personal experience with blockchain's wallet, but i do know that greenaddress atleast is pretty safe because of 2FA, SMS confirmation and you are holding your own keys.
Personally i prefer using Ledger wallet and electrum on PC, and mycelium on android.