Captain FTP

From Applepedia

Captain FTP can be found at: http://captainftp.xdsnet.de/

It's not a free program to use, costs 25 dollars,

The interface is really simple, like cuteftp for windows. It has an address book, and all the standard features you would find in cuteftp. It allows for drag and drop transfers and keep alive. It's full featured and has a neat pirate icon. It also does sftp, so basically if you want an ftp client that does everything, this is it.