FileZilla is absolutely the best freeware FTP program available, not to mention perhaps one of the best overall rivaling commercial clients like CuteFTP or FlashFXP. It comes jam-packed with the most important features and is supported by an open-source oriented developer community.
The interface takes a little getting used to, but if you're familiar with FlashFXP or CuteFTP, it should take little to no time to know your way around. It's super fast.
Version 3.24.0 is a freeware program which does not have restrictions and it's free so it doesn't cost anything.
Virus and Malware Tests: The program has been tested with several antivirus applications and has tested clean of viruses, malware or trojans.