If you need FTP software to upload your website files then we would always recommend using the FTP client that is built into your design software.
If however your software does not have an FTP client built in or you are coding your pages by hand then we would go for cuteftp.com
Microsoft Frontpage Users!
You should however be aware that you should ALWAYS use Microsoft Frontpage to upload your website and nothing else as you risk corrupting your frontpage extensions and will have to re-install them.
Macromedia Dreamweaver Users!
If you are using a firewall (software or hardware) then we would recommend that in order to avoid timeouts during uploading and for improved security you should use "Passive FTP" when uploading files.
What is a Passive FTP Connection?
When you connect to an FTP server and require the transfer of a file or data, you must initiate a second connection. A passive FTP connection is where you connect to the server instead of the server connecting to you. This is necessary when you are hidden behind a firewall or router of some sort and are unable to forward the correct ports to your machine.