These are a great series of videos about the history of the MGS series.It's a great watch for fans of the series.
CAUTION LOTS OF SPOILERS.
Part1:http://www.gametrailers.com/player/33740.html
Part2:http://www.gametrailers.com/player/34187.html
Part3:http://www.gametrailers.com/player/34425.html
Part4:http://www.gametrailers.com/player/34700.html