Need top rated youtube clone plugin

I want to build a WordPress site that has the features of YouTube, ie user upload, automating video conversion thumbnail generation etc. I do not want just embedded content.
I am willing to spend money on this as long as I get the functionality I require. I have trawled through so many scripts on all sorts of levels but they tend to be from dodgy sources and built with teenagers in mind.
Help would be good with this please.