A hardware wallet is definitely the most safe way to go. People have recommended the two most widely used options above...Trezor and Ledger. So those would be the "safest options", provided that you follow all the recommended practices, keep a backup properly etc.

The other way that I recommend, which is frankly mostly because of the convenience (I don't have a huge amount of BTC, if you do, you should probably try a hardware wallet and even better would be to not put all your eggs in one basket, so separate stuff and keep in various wallets...trust me the investment is worth it if you own a considerable amount in BTC), is using Electrum. Its open source, and as long as you know what you're doing - everything's safe and in your hands. Its also very conveniently accessible, that helps.