Trezor. It's worked really well for me. Highly recommended.
They give you a sheet to write down your recovery seed/phrase so that in the event your Trezor is lost/not supported in 30 years/whatever, you can easily recover your wallet by entering the phrase into any popular wallet service, such as Electrum or Mycelium on your phone.
It's a good, foolproof system. But you should play around with it for a bit, exchange some coins to your own wallets, get a feel for the device, then finally move your savings to it and sleep soundly knowing that they are safe and the backup exists.