I looked at both Dropbox and SugarSync for unattended backup purposes (5GB free for sugarsync vs 2GB for dropbox) and went with Sugarsync, because I did not want to think about copying stuff to my dropbox. Plus it already had an android client at the time I evaluated the options, so all my mobile data I care about would automagically appear on my desktop. The downside for Linux users is that it requires an alpha-quality add-on.
Back when I used SugarSync for lots of data, the client software kept crashing. It was also harder to setup.
I have often benefited from recommendations for Things I Didn't Know I Wanted.
Given that Less Wrong is a community of unusually intelligent, critical, and self-improvement-focused people, I suspect we can generate a pretty helpful thread of product recommendations — perhaps even a monthly thread of product recommendations.
Rules: