My solution is to use a NAS server for backup, and backup up the My Documents folder of each user and computer in the house to the NAS server dally, weekly, and monthly. It has worked well for the last two PCs that have died; I've recovered everything I needed on the replacements.

Karen's Replicator is a simple and free way to back up data. It just copies from source to destination, and either can be a local drive, a mapped network drive, or a a UNC folder.

The only thing I don't like about Karen's Replicator is that it is not automated enough ... ideally it would run scheduled back up jobs without prompting. However, as long as I'm logged in, and then switch to another user, the utility reliably backs up.