This is a tough question because all of the brothers I have met from NPHC frats have been the epitome of class and intelligence. However, if I was a dude, I would chose either the Ques or the Iotas.
As for the Ques, they just seemed so good natured and very fun to be around. Even the oldest Ques I have met displayed the same level of love and passion for their orgs as the newest neo, and it seems to keep them eternally young.
As for the Iotas, I have a TREMENDOUS amount of respect for their ability to preserver and prosper these past 40 years. Their growth has been phenomenal, and that says a lot about them as an organization.
Both of these orgs rock some variation of my favorite color (Gold)
So, either one would have been a win-win situation if I was a guy.