I've been looking for something similar, but it's actually to rip a flash file from Newgrounds into the original .swf format. I have some flashes there that I don't want up anymore, but I want to preserve them.
Also KMAN, if you want absolute best quality, a very simple, but tedious way to have something recorded off of YouTube (or any streaming video for that matter) is the video screen capturing in VirtualDub (it's a free software). When you do the capture, you set the capture resolution to that of the video and your drag the video within the capture space and have it recorded with no performance or quality loss whatsoever (depending on what compression you use) and it records off of Windows audio (just be sure not to make any other noises, like from MSN pop-ups or folder clicking, etc..) Then use the cropping tool to take out all the other stuff (the browser and your desktop, for example)
