unbiased rankings

Fraternities
Top: SAE, Sig Ep, Phi Kap
In no particular order, these are the top houses. This isn't about to change unless one of them gets kicked off. SAE and SigEp will never get kicked off due to having many rich alumni and several members on AS, but Phi Kap getting kicked is definitely within the realm of possibility.
Upper MIddle: Phi Psi, Theta Chi
Theta Chi has done well in their 3 years on campus and Phi Psi rebounded nicely from spending most of the 13-14 school year on probation. Each will try to say that they are way better than the other, but in reality they are completely interchangeable with each other.
Middle: AEPI
Not quite as high as Phi Psi or Theta Chi but there is a big dropoff from AEPi to all the houses below them.
Lower Middle: Ksig, FIJI, DU, ZBT
All have decent parties. Ksig would do well to stop thinking they are top tier.
Bottom: Pike, KA, Phi Delt

Sororities
Top: AXO, APHI, Pi Phi
Like the top 3 on the fraternity side, these 3 are interchangeable with each other and regardless of what people say on here, none of the 3 are going to fall from the top tier any time soon unless they get kicked off.
Upper Middle: GPhi
This is really the only place to put them. They aren't top tier, but they are miles ahead of any house that is under them.
Middle: DG, KD
Solidly middle. Like with Phi Psi and Theta Chi, these two are completely interchangeable.
Lower Middle: DZ
Definitely trending upwards but still not as high as DG or KD.
Bottom: AGD