A couple things from the OP. Someone pointed out that people don't talk about Penn much around here. How true. Even Penn
trolling seems to have turned into Chicago trolling.
And why did I choose Penn? I know very specifically what I want to study, and the faculty at Penn is stronger in that area than really anywhere. I'm interested in immigration law and have read law review articles by Adam Cox (the guy who teaches immigration law at Chicago), Howard Chang (Penn), Yale-Lohre? (Cornell), Mark Tushnet (Georgetown), Sullivan?? (Texas), etc. Other schools like Harvard, Columbia, Northwestern, and NYU don't really have anyone teaching immigration law regularly. The rest of them don't ever get into theory or even advocacy, but instead they have some technical expert who could teach black-letter law excellently, but nothing more.
That isn't to say I had all these choices when I was choosing, but even if I had, I'd like to think that I wouldn't have been swayed by the prestige of other schools, because Chang really is
exceptional among the immigration law professors teaching at the elite schools in the country. (Ironically, to this thread at least, he has a Ph.D. in Economics from MIT and brings that perspective into his writing on immigration a lot). If I had to choose a second choice among those I listed, it would be Chicago. If I was willing to expand it a bit to look at UCLA, they have literally a dozen all-star faculty members that I would have loved to study from in this or related fields. Michigan also has an excellent program for this sort of thing.
Ranking immigration programs, mostly based on professors and courses offered, I'd go with:
Penn
UCLA
Georgetown
Michigan
Chicago
Cornell
Something like that, but to be honest, I never looked into Yale because I didn't apply.