@Dr Herbie: This may or may not work for you, but I use CrashPlan+ as it gives me unlimited (woohoo!) backup capacity, the only caveat is that it's only for one PC.
To break it down
1. All data is on one PC, all other PCs have access to that library using a GB Ethernet connection. When Windows 8 is out, we'll setup replicating disks on this.
2. CrashPlan+ is used to replicate #1. The cost is $3 per month for one PC, $6 per month for a household for unlimited data.
3. The most important data is also replicated to SkyDrive
4. Home Server backs up all of the machines, but it may be dying so I'm looking to switch options here for PC backup...
I started using CrashPlan+ 2 months ago, and it's awesome, but I think Dan got it wrong (or I got a different plan). I'm backing up 4 different pcs to each other, and my main system is also backing up to crashplan's servers. I've had to use it twice to restore, once when swapping out a hard drive for an ssd on my laptop, and last week my 1TB e drive died. The restore was simple enough.
I got tired of screwing around with manually figuring out where and how to get my stuff on the right backup.
I still use mesh for sharing files between work and home, though, just because it's easy to use.