Armory with an m-of-n backup with dedicated separate cold wallet and hot wallet computers. Distribute the m-of-n backups geographically and among a couple different safe deposit boxes. In your will write clear instructions on how to recover the coins with the backups. This is the safest way to store coins imo.
What would you need a hot wallet computer for? Other than that, this is a great method.
You use the hot computer to create transactions on a watch-only wallet that you can bring back to the cold wallet to sign. You then bring that transaction back to the hot computer and broadcast it.