Which wallet do you use for storing your ERC-20 token?
I personally like MEW because it's very easy to use. Some people like Trezor or Ledger but personally I have no problems by using MEW

In MEW you have complete access to your private keys.
Ofcourse majority of us use MyEtherWallet because this is the most famous and popular wallet backed by ethereum.though i also used trezor for security purposes i am always having a second opton for plan B so incase MEW fails atleast i have another one to safekeeping my ERC20 /tokens