Our number one pick for FTP application is Transmit. It is solid, and quite full-featured:
Column view. iDisk. sidebar. ftp/ssl. search. zooming. it even has tabs.
What is FTP?
FTP, or File Transfer Protocol, is the universal way to send, receive, and manage your files and folders using the internet. If you manage a web site, need to send a file to a friend running an FTP server, need to post eBay images to a image host, or download a lot of software updates, then Transmit is the perfect program for you: it makes FTP easy and fun!