Which is the most safe storage for doge coin?
cold storage
I agree, if you have 1 mil DOGE or more, then you seriously need to consider securing your funds.
A very safe and easy setup is to get a old computer only used as DOGE wallet (e.g. old laptop), instal a clean OS, instal Dogecoin-QT, copy-paste the public key to a txt file, and transfer the file to a USB stick.
TURN of you Doge wallet computer (now your wallet is "cold").
Transfer funds to the public adr. for your doge wallet - sit back and look at pictures from Hawaii)
cold usb is ok too, don't need a whole computer just for one coin