Storing your bitcoins safely is tentatively relative to how smart the user is at storing it. For a lot of people coinbase would probably be your best bet because I know people that lose they're password and don't have a backup key or they download an update to their wallet but it was a scam to get your coins from your computer. It's a brutal catch 22. Coinbase could freeze you out of your funds at any moment but are you smart enough to not click on the url, or check what your downloading or where your throwing your private key at.