top and middle tiers with explanation

ZTA/ADPI: undisputed top, partially for tradition but both houses have had great PCs in recent years, different vibes but both houses do what they do well
Tri delt/AOPI: both houses have risen in the past few years, pulled in great PCs and have probably the best fraternity relations in the bunch. Guys love them because they are known for being fun and neither house really cares about being perceived as classy. Both houses have stunners, and some extremely average girls as well.
DG/KD: DG used to be top, but in recent years has been slowly declining, fraternity relations aren't what they used to be and past PC was subpar. KD has been riding on the name for the past two years but they threw a horrible rush and the PCs (and snap bids) show it.

Pi Phi/DZ: Upper middle houses with different vibes. Pi phi being known as partying, chill "bros" and DZ is known as more southern and girly. Both houses have some beautiful girls and some not so cute ones. Both houses threw a decent rush and pulled in good PCs, especially in the upperclassmen arena.
Theta: On the decline and pulled in a horrible PC which more than a few have noticed. Does not deserve upper middle status if you ask me as this is based on nothing but status quo.
DPHIE/Chi O: Deeph is all over when it comes to looks yet provide a very specific kind of girl, they're a fun crowd but appeal to a limited amount of frats. Chi O only has relations with Pi Kapp as of late and is known as a more vanilla, less diverse DZ.