Are we really asking which has the most unique nonstops? I'm inclined to guess DXB but since it's so heavy on 777/A380 traffic, I wonder if IST, CDG, or LHR has more destinations served with smaller aircraft. LHR gives you a ton of North/South America cities with slightly smaller widebodies that EK doesn't serve. Since so many airlines serve these routes, I wonder if they add up to outweigh the advantage EK has to secondary Asian cities with 777s.

As for 3-change (4 aircraft) itins, I want to say we had a thread here a long time ago dedicated to those. Specifically, find two cities with commercial airports that take a minimum of 4 flights to connect. Stuff like small-town South America to Pyongyang...