StreamTransport is a popular solution for downloading videos from YouTube, Veoh, Hulu, etc. Its well-known feature is that it can detect and start downloading videos from an open web page without any extra clicks. However it lacks maintenance, and sometimes it just doesn't do the job. Also, even when downoad goes through well, you may need to convert videos (one at a time only), which can take quite some time. Another significant thing to consider - there is no Mac version of StreamTransport. So here you have the list of StreamTransport Mac alternatives to choose the best one for your needs.
The top qualifier is Elmedia Player PRO. It is not a downloader only, it is a high-quality media player that supports all kinds of file types and will satisfy any playback requirements.
Elmedia Player PRO can download from popular video websites like YouTube, Metacafe, Vimeo, Dailymotion, Facebook and more and from many other video resources. RTMP streams and HTML5 videos are included. What the latter means is that when other downloader fail to download from a news channel, most probably Elmedia will be able to help. If there are subtitles available with the downloaded video, you can download it and save as SRT file with Elmedia.
Another worthy Mac alternative to StreamTransport is a very simple app that conquers its users with simplicity of use and lightness, however only supports YouTube. Airy downloads YouTube videos in various resolutions (HD and full HD included), and can save whole YouTube playlists and channels to your Mac. Another cool thing about YouTube downloading with Airy is that you can extract MP3 sound out of any YouTube video. Airy can also do something many other apps can't - it can download private videos from YouTube.
KeepVid Video Downloader is a free web service letting you download from YouTube, Facebook, Twitch.Tv, Dailymotion and other similar video services. The KeepVid service is easy to use - paste the link to YouTube video in a corresponding box and you'll see all available download links for your video. KeepVid allows converting videos to lots of formats: WMA, WAV, MP3, AVI, MP4, AIFF, FLV, MOV and MPEG.