What is the best replacement for disk drives?

We have been using disk drives for years and optical drives seem to work. But both are prone to fail, what do you think is the next replacement for them?
I think internet storage is a good way to save files after a drive crash. But you need to reload your system and reconnect to your internet drive first. I also think that flash drive technology is the way to go for new computers.
With a flash drive there is no working parts so it is less likely to fail and the whole drive is less then any disk or optical drive