Mega - The Most Trusted, Best-Protected Cloud Storage

You can get up to 20 GB of free cloud storage with MEGA. It offers secure end-to-end encryption to help combat a breach of privacy. If you complete tasks, you can get the full 20 GB without paying.

One interesting feature is the ability to share links in a way where the recipient needs a second part of the URL, basically like a password, before they can decrypt the information.