I like SmartFTP best, probably because I have used it for so long. But have to say I use the one that works. Some sites I have to use FlashFXP ( if they are behind a router too), others Cute works best. That's my main ones, Smart, Flash and Cute
I´m with RedBully, FlashFXP does the job all the way.
I think I have tried every single FTP client´s that excist, but none except FlashFXP can take care of the stuff that I wan´t/need. It just rocks, simple as that.
one unfortunate thing that flashfxp fails to do that i like smartftp for is that it allow you to see all those nameless folders like... pub/download/ /...
so i go with both smartftp [being freeware also helps my argument] and flashfxp. unbeatable combination.
Flash all the way. It never gives me a problem. In WS_ftp I had a harder time configuring and when I used bulletproof I had a "registration" problem.... hem hem.... with it.