I think Crashplan is great. It has a couple quirks, and their software could use some work, but that's not a big deal because I never have to actually use the software. Everything is just backed up and I don't have to think about it. The only times I think about it are once a week when I get an email telling me how backed up my various computers are (including various family members).

It's the least expensive service with the most features. I don't know how long that'll hold, and they could be out of business in a couple years, but at that time I can just switch to another backup provider.