Ledger Nano S is the best available hardware wallet at the time of writing this article. It's made by company based in France specialized in Bitcoin security. The best thing of Ledger Nano S is that it supports Bitcoin as well variety of altcoins and the list constantly expand. You can securely store BTC, LTC, ETH, Ripple etc.
One of the major things over other wallets is that Nano S signs the transactions offline, so the private keys never leave the wallet and it's completely safe for storage big amounts of cryptos.

The Nano S has a screen so it helps you verify and confirm all outgoing transactions, which provides additional security.

Which altcoins and tokens are supported by the Ledger Nano S?

Ledger Nano S natively support:

Bitcoin
Bitcoin Cash
Ethereum
Ethereum Classic
Dogecoin
Litecoin
Zcash
Dash
Ripple
Stratis
Komodo
PoSW

Some other Ethereum tokens (ERC20 tokens) can be managed using Ledger Nano S and Ledger Blue with MyEtherWallet only:

1ST
ANT
ARC
BAT
BeerCoin
BCDN
BNT
CFI
CRB
CryptoCarbon
DAO
DAO_extraBalance
DGD
DGX 1.0
EDG
EMV
GNO
GNT
GUP
GT
HKG
HMQ
ICN
JET
LUN
MCAP
MCO
MGO
MDA
MIT
MKR
MLN
MNE
MYST
NxC
PAY
PTOY
PLU
QAU
QRL
REP
RLC
RLT
DICE
ROUND
SGT
SNGLS
SRC
SWT
TaaS
TIME
TKN
TRST
Unicorn
VSL
VERI
WINGS
XAUR