I use FileZilla for FTP, though Cyberduck has excellent Finder integration. I simply do not use Cyberduck because of the name. (Also because I use FileZilla on Windows).
Perian is a good add on for QT player for playing various divx/xvid and other encodes in QT, but I use VLC most of the time.
There is no good, free archiving utility for OS X. I have to use both Unarchiver and UnrarX to cover most of the bases, and both have awful UIs. I guess I'll try 7zX and use p7zip if I must.