Recently, Behind the Blocks' Priyant interviewed Dutch relay gold medalist Ranomi Kromowidjojo. In introducing the article, he mentioned that if the Dutch women win the 4x100 Free Relay in Rome, they would be the greatest relay in history, with the same four girls winning the relay at World Short Course and Long Course, European Short Course and Long Course, and Olympics. (Not exactly true as there was a substitution at World Short Course, and there's only 4x50 at European Short Course.) I think it's a great quartet, but the greatest ever?
To be considered the greatest relay in history in my opinion, a team must dominate the event over a long period of time. The one that comes to mind for me is the American 4x200 Free Relay. At the 2004 Olympics, Michael Phelps, Ryan Lochte, Peter Vanderkaay, and Klete Keller took gold. At the next two World Championships and well as Pan Pacs, the same four men continued winning, each time getting faster and extending their winning margin. In Beijing, Ricky Berens was substituted for Klete Keller, but if Keller had swum, the Americans would still have won by five seconds and broken seven minutes. The only slightly comparable relay would be the medley relay of Peirsol, Hansen, Crocker/Phelps, and Lezak, which won every major meet from 2002-2008 other than 2007 Melbourne when they were DQ'ed. But is a relay is judged to be "greatest" by its complete dominance over a long period of time, the American men's 4x200 wins out.