There is no doubt that DAP and Orbit Downloader are the 2 of the most popular download managers as of today. Especially Orbit downloader, due to its multi-functional set of features. But Gigaget is quite the same as well. It also has the Next Grid Technology with multi-threaded functionality.
Once the you install Gigaget, it will seamlessly integrate itself into your default browser. the download speed is as good as DAP and Orbit downloader (if not more than them). Ofcourse, it is free to use and works on Windows XP, Windows Vista, and Windows 7. Gigaget might not be the best, but you can certainly consider it an alternative to popular download managers such as, DAP, FlashGet, and Orbit Downloader.