blockchain.info (soon moves to blockchain.com) is hardly the safest wallet
it is undoubtedly the most widely used web wallet because its easiness to use

IMO, Hardware wallets would be the safest, https://en.bitcoin.it/wiki/Hardware_wallet
they are deemed as safest because private keys never leave the device
although you can still lose your coins if your pc has been compromised by clipboard virus/malware
Trezor and Ledger wallets are the two most popular hardware wallets