Right now my fav is Freemake Video Downloader, very easy to use - one button, then choose quality and format. I myself, for reasons of posting to PTZ, always go with the highest quality FLV download I can make.
As for mentioning PTZ on YT - its has always been a roll of the dice. I feel most video creators deserve to know their vid is going to be on PTZ - which is also why I am a stickler about credits. Perhaps in comes from writing and also knowing waaaay to much copyright and intellectual property law. But it is only once in a great while that someone pulls their video from YT on account of PTZ - my experience has been that they got blasted by some YT troll(s), or too much criticism for something they put up not really for a wide audience beyond their family and friends. :)
But I will downloading videos as soon as I first lay eyes on them from now on! LOL!
I will take a look at YouTube Downloader - I find it is always good to have a back-up program, in case things change and suddenly your program no longer recognizes a file, or one of a thousand other glitches inherent in technology land!
Just Pop It!