Not to slight IAA, VE, and other alliances which have disbanded and reformed, I'm not sure its fair to include them (numbered at least) in the main list. For example, NADC has existed for much longer total time than VE (in either of its incarnations) has.
I mean, if tomorrow people (even if it was Ninja and Chris Miller themselves) posted saying that they were reviving the ICN, would we place them at #2 behind GATO?