cyberduck

Cyberduck

I think Cyberduck is the most user-friendly FTP app out there (too bad it is only for Mac). I was introduced to it a few years ago when I was just barely grasping the concept of FTP and I could connect to different servers & upload files within minutes. Currently the software allows you to browse servers using the following protocols: FTP, FTP/TLS, sFTP, WebDav and browse & upload to Amazon and Mosso's Cloud Storage.