There are a lot of existing FTP client, may they be software, freeware or web-based applications. Each one of them has their own way of saying that their product is better than others are. Of course, that is marketing. But Wikipedia has an entry about FTP client comparison. You might want to take a quick look at it of you are planning to have purchase or to acquire an FTP client.
The article compares general information and technical assets of some popular and usual FTP clients and other clients that uses the same protocols. Although the article is not always updated, it is still a help.