Armory M of N backup of an offline created wallet stored in multiple different physical locations.

I would do something you haven't mentioned on these polls:

. Put the coins on a laptop

. Put the coins in an offline armoury wallet

. disconnect the laptop from the internet until you actually need to coins to spend

. If you're really paranoid, stick the laptop in a safe where no one can get at it

Why would I use a laptop? If you need to run off and you want to transfer your coins somewhere the laptop has everything you need and after that you just need to enable wi-fi again and can transfer the coins somewhere else, virtual servers and the like would only be safe depending on certain situations but for most people I think a laptop would be best another reason being that USB's would be far too easy to lose because of their size and you wouldn't notice if someone took it.

I can understand the idea of paper wallets but I think they're ridiculous, like fiat money they're easy to tear and you can set them on fire pretty easily, not something I would have a lot of money attached to.