I've been using rsnapshot for awhile and have liked it quite a bit. For awhile, I was using Duplicity, and although I liked the compression and encryption, it struck me as being a bit buggy and unreliable (not what you want from your back-up system). I've never used LuckyBackup, so I can't say much about it.
Amanda and Bacula seem popular, but they're a bit more complex and perhaps more suited for large environments. Really, it comes down to what your needs are and what you're comfortable with.