I've tried the free versions of Smart FTP and CoffeeCup FTP, and I don't like either of them. CoffeeCup is far too limited, and Smart is way more than I want, need, or understand (I have adult ADD). WS_FTP95 has a straightforward interface and just enough features to keep me happy. At the moment, I don't have a website, though that could change in the near future. For now, I just use the client for downloading from sites that offer FTP access. I'd consider the current paid version, but it's a bit pricey at about $40 for how I'd use it (and other ways I could use that 40 bucks!
Amazingly enough, it seems to operate just fine in Windows Vista. Can anyone provide some good reasons why I shouldn't continue using it? Security is the only thing I can think of, but I don't know enough about security vis-a-vis FTP clients to make that decision on my own.