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.
Riseup also offers email, XMPP, chat and data hosting (via Up1) services, all of which are accessible through Tor Hidden Service addresses. The list of these addresses is available here.
DuckDuckGo is a software-as-a-service (SaaS) hosted around the world that provides you with anonymous search results from these sources. DDG open source components are available here.
There is also a DuckDuckGo hidden service at 3g2upl4pq6kufc4m.onion for Tor users.
MetaGer is a SaaS by the German non-profit SUMA e.V. that provides you with anonymous meta search results.
Startpage is a SaaS hosted in the USA and the Netherlands that provides you with anonymous Google search and image results through a free proxy.