I use plain ole Winzip to back up my data to a second machine in my home and to a remote FTP server to which I have free access at the moment. The advantages:
1. No proprietary protocols involved; whenever I want to I can either read or write using different software or different servers.
2. Very easy to script and automate.
3. Many other uses unrelated to backing up.
There are many free programs which claim to be as good as Winzip, but I've never found one which is so easy to script and which can *really* handle multiple large files over both FTP and SMB.
Winzip costs money, but there's a free trial. And don't forget that noone forces you to update every time they *claim* that they've got a revolutionary new update which is worth paying for. As with other such programs, you read the New Features list and decide for yourself whether you consider the new features worth paying for.