FileZilla - Download open-source FTP client
You can download or upload several files from and to several servers simultaneously. If you have some limitation on your bandwith, you will enjoy it, because Filezilla enables you to automatically adjust speed transferring based on the time of day or date. You can also browse FTP sites mid-transfer. The filter will show you only the files that you need.
This program has a simple and comfortable interface with multiple languages. Due to the cashing directories the speed of browsing of FTP sites is fast, multiple secure connection options provide the file transferring over the internet. It has two types of bookmarking - the Site Manager for all your major FTP locations, and QuickConnect for fast switching.
Filezilla will not take a lot of place on your computer. It is obviously that Filezilla is the best aid.