As long as your private keys are safe your bitcoin is safe. Because it is merely impossible to breach into another's wallet without knowing private keys. So keep your private keys safe. Best use offline wallet to ensure security.
Yes, this is probably the most sane comment here. Rather than focusing on what type of wallet to use, concentrate on the keys. However, any online wallet is essentially trusting a 3rd party to do a good job with security, which, as we've seen, they don't tend to be very good at.