Verified answer

I'd recommend using https://www.mega.co.nz/

They offer 50GB free storage space, no ads, faster download/upload speed than any other, all your files are encrypted, there's no max upload limit per file and they take your privacy very seriously.

That would depend on how much space you need. You can find an excellent article at http://edatadoctor.com/data-security/ that provides a few options.