what are the real sorority rankings here?

First of all, let me say EMPHATICALLY that all 7 chapters at MSU are great chapters. At most other schools, even the "lower tier" chapters would be highly competitive groups. With that being said, I'll just give you this as a "most people agree that..." statement. Take it with a grain of salt.
Top Groups - DG & Chi O
Still really good - KD
Solid Mid-tier - Phi Mu
Very Good, but struggles to get "top" rushees - Tri Delt
Solid groups, but usually take rushees other groups have released - Pi Phi, ZTA

agree with the previous statement.

Chi O and DG consistently pledge top girls and keep them for 4 years. These two groups dominate every organization on the MSU campus and are always in leadership positions. Also top two scholarship year in and year out.

KD is a wonderful group of ladies. They pledge top girls too but can't retain as many members as the other top 2 groups. They are fairly involved on campus but don't dominate.

Phi Mu seems to get a really good pledge class followed by a couple of ok ones. They can't quite seem to step up to match KD. Close but just not quite there.

Tri Delt, Pi Phi and Zeta have good members but get the girls that the others cut. They all work hard to be involved and contribute on campus.

Even if you aren't in the top 2 you can agree that the posts above have it right. Thats how everyone on campus views the houses. The only ones that disagree are Phi Mu's...

Even if you aren't in the top 2 you can agree that the posts above have it right. Thats how everyone on campus views the houses. The only ones that disagree are Phi Mu's...

By the recent pledge class I'd say:
DG
Chi O
Phi Mu
KD
Pi Phi
DDD
ZTA

Chi O had the top pledge class hands down. DG's was strong but not tops. This is what all of the guys are saying:

Chi O
KD
Phi Mu
KD

Chi O and DG's are totally tied, they both have SO many girls whose names I heard all week. Both are super strong. Phi mu MIGHT have one to give KD a run for their money. A lot of girls I thought would be KD's went Phi Mu instead. Interesting to see how everyone will do this year. Until then, I think it's:
Chi O/DG
Phi Mu
KD

There are more than just 4 sororities at this school.. I know the rest aren't up to YOUR level of superiority but we still matter and should NOT be left out.

REAL sororities are not tiered...only those that still have a high school mentality rank sororities (and fraternities). Each sorority is tops in any given field. If you want a popularity contest then your are in the greek system for the WRONG reason. Each sorority has its strength and weakness...This is not high school ..these are organizations that you join to become part of a group and enhance your college experience. Each person is going to be attracted to something different. It is interesting that people want to put a RANK on a sorority.....grow up....there are only so many girls one sorority can take so there are many good girls in ALL the sororities...and each girl thinks her sorority is the greatest and that is what it is all about...

If you know anything about MSU greek life you went into rush focused on 4 sororities. It's the truth here. 4 chapters are better than the 3 others. 1 of the 3 is getting better and maybe it will be 5 in a few years over 2 or 3 if ADPi stays. It's not nice or politically correct, but it's life. It is a popularity contest and no one goes in attracted to the least popular. They might be happy by the end of it but I doubt anyone goes to every water party and thinks that any of the 3 are better than any of the 4. There is a reason those 4 are the best, and thats just how it is.