I second Crashplan. I use it to back up a directory of my office machine (2GB at the moment) where I keep all the current project stuff, including Outlook archives for the last 3-years of emails.

The whole directory is inside a Truecrypt disk, btw (but I am running Crashplan after mounting the Truecrypt volume, so for Crashplan the files are visible).

I did a few (say half a dozen in the last 3-years) restores of a specific file and I did a full restore of the whole directory to a completely different machine (a Mac) due to problems with my old laptop - they replaced the HD and I had to keep working for a couple of days before getting it back.

And another full restore when they finally replaced the laptop with a new one.

In all these cases it worked without a hitch.

I also played a bit with their "backup to a friend's computer" thing, but haven't tested it in depth. Never used their online version, though, so I can't say anything about that.

Another Crashplan user here. When I reinstalled Windows, I restored a whole account (user files, not system files) from a previous backup and it worked fine. It's not very fast on either direction, but I never had any issues with it.

I've restored over 100gb from cp without issue. The most important feature is multiple offsite backups with their free p2p system. My data is in my basement, across town at 3 different friends' houses, and another copy across the country. Nothing short of a meteor strike will cause data loss at this point. And it's free.

I've currently backed up over 400gb but have only ever had to restore about 100gb. That experience was fine, with no issues. I guess I can't say I have ever done a full restore though.

I restored (my Mac and another machine) from Crashplan several times when they failed and had no problems.

I was restoring them from Crashplan backups on my Synology though, the Crashplan servers can be kinda slow at times (in range of 10-30Mbit/s transfers).

I had only one strange thing happening in ~3 years of using Crashplan. I'm using it for cloud backups but also for "friend" backups - with all the systems backing up to a NAS with Crashplan installed. A month ago my parents had a problem with some files in one folder (bad sectors on the HDD), and I had to recover them from the NAS (their system backs up on the NAS). Using Crashplan on their system, I could only restore about 30% of the files - the others were not listed at all. Recovering the full folder using their Crashplan resulted in ~1.5GB of files. Doing the same on my NAS, I could see all the files and I could successfully recover >4GB of files (all of them). Somehow their Crashplan could not see all the files it backed up, but the target Crashplan did.

No idea if this is expected (their account is a free one, where you cannot change many of the retention and backup settings) or it's a bug, but this made me check the cloud backup also and compare the files on the disk with the recovered ones. No problems so far, but I only managed 1TB (of 2.5TB backed up).