Tetris is by far the most popular and probably most addictive puzzle game there is. One dude, obviously from Japan, named TGM Holic / jin8 knows this game inside out. This is apparently his choice in life: to kick everybody's ass playing Tetris. The video clip below shows his total dedication.
Watch as he kills, and then at 03:03 he kills even more - just to finish off with playing the game in invisible mode!