Good SFTP Clients?

Joel Parker Henderson writes "To improve security, my company is switching servers from Microsoft to RedHat, and from FTP to SFTP. The new RedHat has SFTP-- secure FTP with SSH and host fingerprints-- and I want to upgrade our people to use it. What are good SFTP clients? Priorities: an easy user interface, point-and-click renaming of remote files and folders, recursive directory transfers. Useful: drag-and-drop, resume broken transfers, synchronization of local and remote directories, written in Java, shareware or freeware. Thanks in advance for advice!"