Actually the safest wallet to keep your bitcoins is actually a hardware wallet (Cold storage). Hardware wallets are actually small devices that connect to the internet just to enact transactions only. They are very secure as they are often kept off the internet system and thereby not hackable .Examples will be Trezor T or Legner Nano S. I personally prefer Legner Nano S.

For a online wallet ,i personally prefer Jaxx as it allows me to keep my private keys to myself. However , such wallets are prone to hacking as there are based online. So it will be advisable to scan your computer for malware every now and then.

For exchanged linked wallet, Coinbase is a good wallet then have 2FA protection ,Email protection and IP address notification.