YouTube and similar sites

YouTube is the biggest video site on the web today, it is rated the number 4 site in the world by Alexa rating. Statistics shows that more than 95% of the internet user have visited YouTube or seen a video hosted on YouTube.
During the years many sites have tried to clone YouTube or to set as an alternative, the best example was Google video, a video service from the giant internet company who failed and pushed Google to buy YouTube at an enormous price.
Today there are some sites like YouTube, some of them are more niche sites but some are proud to be mainstream video sites.
Here is a list of similar sites to YouTube.