FlashFXP is a very capable commercial FTP client.
The program supports all the file transfer standards you need: FTP, SFTP, FTPS, site-to-site transfers (FXP), SSL site-to-site transfers SSCN), and more.
The transfer process itself is usually as easy as dragging and dropping. And on-the-fly MODE Z compression ensures the best possible performance. But if you're moving a large number of files and don't want to tie up all your bandwidth, then you can also set the program's maximum file transfer speed in just a click or two.
And there's plenty more. You get convenient file management; easy remote file editing with automatic upload on save; a remove server file search; a priority transfer list; the ability to calculate the size of all files in a specified path, and extensive command line switches.
As there's plenty of free competition FlashFXP inevitably still looks a little expensive, but it does have plenty of features, and if the free tools leave you unimpressed then the program just might appeal.
Version 188.8.131.527 is a maintenance release.