IMHO the most reliable RTMP Flash stream recorders are Replay Media Catcher and Jaksta. I don't recommend FLV Recorder and Bit Recorder due to lack of necessary updates and support.

Orbit Downloader is free and its a big advantage, but it is not a good RTMP downloader.

Please note that software like Replay Media Catcher can download 75% of the stream in the demo mode, so you need to buy it in order to download 100% of the video. The same it with Jaksta.

NetXFer can download 100% of the stream in the trial mode. It supports RTMP streams as well.