I've been playing around with some shareware (is that an old term now?) for backing up software and have really had good results with Cobian Backup

http://www.educ.umu.se/~cobian/cobianbackup.htm

They have two versions, 8 and 9.

Version 8 is available still as it remains Open Source and presumably customizable. Version 9 (Amanita) is not open source but is still free.

I'd like to see some new features like an archive/delete option, among others. I get the feeling they're moving to a pay version. But if it's only a few bucks and have some extra features, I won't be surprised if it's worth it.