"Me too" for Crashplan. I would never advocate cloud storage as the only mechanism, but as an addition to existing local/near-local backup it makes sense to me.
Yes, the first backup can take a while, but every image/file uploaded is one more that has that extra level of protection for the extreme case of losing all local backup.
Given the value of the data, I consider the cost to be negligible, with Crashplan offering one of the better stories.
FWIW, I have a smaller set of files also backed up to Carbonite. Overall I prefer Crashplan. Ditched Mozy and Spideroak for various reasons that don't invalidate their service per se (such as price).
I'm aware that some very large companies also use Crashplan software, which I take as a vote to the company's underlying stability.