youtube downloaders

ok i have tried several downloaders , none of which work , all of them have some issues
most of the time they will say its converting to mp3 {i use switch} but the finished file is only seconds long
i have tried the ones of the apple website they didnt work
try Firefox add on=Flash and video downloader, and Youtube downloader add on. Both work pretty good. If u cant download using these addons then try to view the whole video and then look in /User/Library/Caches/ur web browser folder/Cache/ then click on each file "get info" and see which one of those is a big video file like 5mb or more and add extension .flv to it and play it to see if it the correct video and then drag it to a desired location because if u dont then the next time u clean or reset ur browser that data will be erased for ever.