My vote is for paper wallets where you have multiple backup copies.

Online accounts like Mt. Gox and Coinbase are my absolute _last_ choice.  The former went out of business, the latter ate their customer's value in bitcoin cash.  That's a hard veto.

An electronic wallet can be lost to a cyberattack, hardware failure, or I could forget the damn password.  If I'm smart and write down the password and keep backups and never connect that system to the internet then I can avoid those.  That is all more complex than a paper wallet.

You might talk me into a multisignature paper wallet, with the keys stored separately in audit-able tamper evident ways in secure locations.  I'm hesitant about that though, since loss of n keys can cause the entire sum to become inaccessible