There are lot of video formats and there are further more number of video codecs required to play specific videos. Installing a codec to play few videos may not be too exciting and here is an alternative to get out of vicious circle of video format and codecs. MakeInstantPlayer is free
Chat & Watch Videos together with Messenger TV
Get set to watch videos and chat with friends simultaneously with Messenger TV. It allows you to watch MSN Videos with a friend as you have live text conversations about the videos you are watching together. Similar to watching television with your friends, you can watch videos and chat