sororities w/highest academic standards

Typically, if you're above a 3.0, you're good! Some chapters do rank you based on your GPA though, but it won't make you or break you because they rank on other things too (like your personality/if you'd fit in with the chapter), so I wouldn't worry about it. The chapters that focus on GPA the most are: Theta, ADPi, AOPi, ASA, and Phi Mu as they've had the highest GPAs in the past.

I wouldn't worry too much about it though and just let your personality shine! Yes, grades are important but it won't be the only thing a chapter will focus on.

If finding a chapter that focuses on GPA/academics is important to you, here were the GPAs from Spring 2016 semester. This doesn't mean these chapters always have the highest or always have the lowest GPAs but typically. (source: student affairs)
Those with top GPAs Spring semester:
1. ADPi (highest)
2. AOPi
3. Theta
4. Phi Mu
5. AXO
6. ASA

Those with the lowest GPAs Spring semester:
1. SDT
2. Kappa
3. A Phi
4. DPhiE
5. Tri Delt
6. SK (lowest)

If finding a chapter that focuses on GPA/academics is important to you, here were the GPAs from Spring 2016 semester. This doesn't mean these chapters always have the highest or always have the lowest GPAs but typically. (source: student affairs)
Those with top GPAs Spring semester:
1. ADPi (highest)
2. AOPi
3. Theta
4. Phi Mu
5. AXO
6. ASA

Those with the lowest GPAs Spring semester:
1. SDT
2. Kappa
3. A Phi
4. DPhiE
5. Tri Delt
6. SK (lowest)

Here's the full list, and SK isn't the lowest, I think you forgot AEPhi:

ADPi
AOPi
Theta
Phi Mu
AXO
ASA
ZTA
AGD
TPA
KD
Pi Phi
DZ
XO
GPhi
AXiD
DG
SDT
Kappa
Aphi
DPhiE
TriDelt
SK
AEPhi

delta