Youtuber Antti Kokkonen, who uploads Let's Plays to Youtube under the username Zemalf, is one of the best XCOM players in the world. On January 11, he finished a 50 hour run of XCOM: Enemy Within on Impossible Ironman difficulty without losing a single country. Or Interceptor. Or mission. Or soldier.
It was a perfect run on the game's hardest difficulty (and his first time through the game).