The main value of MyEtherWallet is that it does not transfer your private keys to third parties, it keeps them only on your computer in encrypted form. Only you can see them.
I use this wallet to participate in most ICOs as well as Ethereum transfers. Remember about sterility: if you have indicated your wallet address on dubious sites, be sure to install a new wallet.
At the moment, it is a recognized standard for usability, security level, the size of the list of supported currencies and tokens. Best used in conjunction with a hardware wallet.