Davids. His dominance of the centre of the park was the platform for the great Holland and Juventus sides of the late 1990s. In the Team the Tournament for both World Cup 1998 and Euro 2000. At the 1998 World Cup, he ran the midfield in the second round against Yugoslavia (scoring an injury time winner), against Argentina in a superb quarter final, and again against Brazil in a semi-final the Dutch lost because of profligacy in front of goal. At Euro 2000, more of the same at the business end of the tournament. He was the clear leader of Holland's midfield in 1998 and 2000 and it was Philip Cocu and Ronald De Boer who were the nearest performers. Seedorf was a decent cog in the system, but his presence wasn't really missed in those big knockout games in 1998. Same early on at Ajax as well where Davids was more influential in running games alongside Rijkaard.
To Seedorf's credit I struggle to think of anyone who was better at rounding off a midfield. He was such an all-rounder who could perform centrally or out wide that, when anything was missing in a midfield, he could usually provide. And although he was generally brilliant support act through most of his career, latterly with Milan and particularly around 2006/07 he became more of a central figure critical to their success.