I don't know if your question is in jest or serious, so here goes. IF it is serious.
I have one reference site that may prove my point. Go to www.ugu.com and see how many versions of UNIX there are documented. On this site, there are at least 80 Proprietary versions of UNIX http://www.ugu.com/sui/ugu/show?ugu.flavors, .
I wish I could post an attachment I have that shows the history of UNIX evolution. It documents 40 different times that UNIX had significant changes up to 1993 from 1969 when Multics was the original incarnation then on to UNIX, and then Version V (5), BSD and SCO Xenix.
These are the 3 major strands of UNIX-based OSs.
One group is SCO UNIX another is based on the BSD Berkeley version and "System V" being the other. These 3 different philosopies are the 3 main dominant ones although there are many variations of them.
There are actually 8 different strands that I know of according to the image I have. Here they are:
SCO(Xenix) , IBM, AT&T ( System V), SIEMENS, BERKELEY (BSD), SUN, DEC, HP
Of the proprietary versions, these are the most robust:
HP, SUN, AIX, but they all have strengths and weaknesses.
Of the Linux versions RedHat, Mandrake, Suse, BSD, etc... the same thing applies. Many people have there favorites, but there is not one that is dominant so far as functionality or methodology.
So far as I know, there is only the historical evolution of UNIX, if that is what you mean. You can trace the history of the creation and variants and off-shoots, but there is no singular UNIX Version that is the Granddaddy of them all, in the respect that you are trying to ascertain.
I hope this helps you understand the futility of your quest and why it can never be determined. Certainly there are dominant ones in this group, but none that are the "be all, end all" of UNIX.