I use myetherwallet more than 1 year. This is Ethereum's official wallet. I think it's safe. Recommend.
MEW is safe and as others said that it has been one of the most known ethereum wallet.
But for security when you are negligible about the warnings of other members here, its possible that you can be a victim and your MEW can be hacked.
As for keeping your ETH this will be the best choice and I have mine too.
Ledger Nano S is indeed beautiful hardware wallet that will offer you peace of mind and a full night time sleep.