Considering the four factors that define a entrepreneurship, Youtube can be considered as a very entrepreneurial venture. It was a big risk taken on by the founders as they had $11.5 million investment start up fund from Sequoia Capital, which is a major risk as it was not guarentied any returns. The idea behind Youtube is also very innovative as there was nothing close to what Youtube is now at the time, a site where anybody with internet access could post a video and voice their opinion, do something stupid or just share videos with friends and family in such an easy way.
There was also immense wealth created by this, as only a year later the company was sold to Google for $1.65 billion, which is a almost 14,000% growth for the start up of $11.5 million. So the wealth was generated really fast, in one year, and the size of the wealth creation was huge. Therefore in my opinion Youtube can be considered one of the best example of entrepreneurship in recent years.
Sources used:
Youtube About (in icelandic, because of my settings but at least you know where it is from)