Why not MEGA? While MEGA is free as in beer, the software is proprietary code.
Why not SpiderOak? SpiderOak is proprietary software.
Why not Tarsnap? Tarsnap is partially proprietary and hosts your data on Amazon Web Services.
Disclaimer: Using the recommended projects on this site will not guarantee that 100% of your communications will be shielded against surveillance states. Please do your own research before trusting these softwares with sensitive information.