Sorry for this late reply, but: FTP is so 20th century. Check out [link] it's secure, it support ssh key-based authentication, and it's a mounted drive, so it just on as soon as Windows starts. (For Linux there's just SSHfs, CIFSfs/SMBfs and NFS of course.)
At work (i.e. on windows) it is total commander or the builtin one that ships with webmin.
On Linux/GNOME I use Nautilus, which is the native file manager, which, thanks to FUSE, has support for a thousand of file-systems; and that even though ftp is not a filesystem but just a transfer protocol. So basically, I don't need an extra [link] there, which is awesome
Fuer hand gebastelte batches nehm ich immer noch den cmd line ftp von Windows, obwohl CuteFTP da auch einiges bietet, habe mich damit aber leider noch nicht beschaeftigt und beim Windows FTP weiss ich halt wie es geht
Just Opera! Nothing else needed. FTP is a simple thing, a good browser should be able to handle it. Actually, it's so long ago that I used something else (5 years at least) that I forgot what it was. Most likely: [link]
For some quick uploads FileZilla is perfect. But for some more complecs sites, when you need to upload/download/edit/update/synchronise many files and versions, it lacks many features (most important: live synch of local and remote dir - for me absolutely necessary when messing with PHP). Then I launch WinSCP It's much more complicated but also way more powerful. It also supports many types of secured connection (also with certificates).
WinSCP is generally best choice for power users and more-than-occasional web developers For any other: FileZilla.