I watch tons of videos on-line in any given week from sites like youtube.com, dailymotion, and newgrounds.
From time to time I stumble across videos that I would love to keep in my video collections. The way that I save the videos is by saving the browser cache folder and searching for the video within there.
To simplify this process I use VideoCacheView from Nirsoft.net.
VideoCacheView is freeware and easy to use. All you do is download and extract the zip file, then launch the program.

Example
Let’s say that I want to download “TFS Abridged Parody Episode 24” from youtube.com.

. All I would have to do are two step to get the file.
Step 1: Open the link and have the video load to the completion.
Step 2: After that launch VideoCacheView.exe and right click on the temporary file to save the video.
That’s it.

Video Cache View Right click to save

Once last thing. Most of the videos are in the flv file format. To solve this problem, you can use “iWisoft Free Video Converter” to convert from one file format to another, like wmv or avi.

Video Cache View: Download here