FTP Commander is simple and easy to use ftp client. It's really the bare minimum with no extra frills or thrills. It offers a no-nonsense interface consisting of two side-by-side local computer and FTP server panels. We use this client almost exclusively ourselves on our sites.
Use Pathbuddy to quickly access freqeuntly used folders. Define shortcuts (links) to folders that can be used in the Windows File Explorer, Open and Save Dialogs or directly from the Desktop. Access the shortcuts with Hotkeys, a Mouse Menu or a Hotkey driven Dropdown Box.