Ftp program I like to use the most is called FlashFxp its good cause you can log on to 2 ftps and transfer files from each of your site. I havent had any problems with it
I think CuteFTP is the best one out there. It's not free, but if you can buy it its awesome! Very easy to use. I have tryed many FTP programs, but CuteFTP was the best one.