puting youtube videos on your page to increase ranking

I was wondering i hear people take really popular youtube videos and put them on there site. Saying that they ride off the page rank of the video. Youtube videos are no follow yet people are saying there geting great results. Anyone have any experience in this? Would a video thats been around for a long time with a high number of views be best? Older videos with high views could be up to page rank 4. Or newest videos with the highest number of views. They have no pagerank but get traffic very rapidly.

their* site

Yes the links are no follow but still it gives a backlink i guess

thanks so would you say it better to get a new video geting super high amount of traffic or a video that get high amount of traffic for a long time now?

YouTube is a very high authority site, so even if it's a no follow link, it's sharing the authority and the PR is nice. Not all no-follow links are bad.