I've tried all the free backup programs, and each one had one issue or another, They simply were not reliable around a year ago.
GoodSync is an excellent backup program with a free trial. It analyses your proposed backup, clearly tells you what will happen, and clearly lets you know if any problems occurred during the backup job. It synchronizes across networks, or locally, and one license will handle multiple computers if they are networked.
Encryption is a non-issue for me, since I use TrueCrypt which encrypts/decrypts on the fly. The backup program isn't aware that it's working with encrypted data, because plain text is fed to it from the encrypted containers.