LastVid is something like a search engine for video playlists. But there are various ways to make a choice. The service uses YouTube as a source and combines this with the recommendation engine of Last.fm, where the service obviously got the name from.
In the result there are endless music video playlists, which may become startet by choosing a genre or an artist. Mostly there are various versions available like live and studio versions. To find a starting video there is a search engine and a context menu available. The videos do start within a website player, which again offers various ways to proceed. Members of Last.fm may associate their accounts and playlists with LastVid to get video playlists.
Similar services are available at music videos.