this needs to be said

Calling any sorority "top tier," or "second best," is just purely banter between sorority women. Each sorority has it's own personality. You couldnt say which character from Pretty Little Liars is the best because they each have their own personalities and are good in their own way.
ADPi would be Allison: the "it girl," probably gets good grades and holds leadership roles. Very typical sorority types.
Chi O would be Hannah or Aria: the creative types who are fun and laid back. Sisterhood and Socials are their main objectives.
AXO would be Spencer: academically inclined and not as focused on social life as they are sisterhood and academics. Not "sororityty."
Tri-Sig would be Mona (out of the institution,): unpopular girls turned sorority girls. They try to fit in and put in a lot of effort with their philanthropy. Really a mixed bag of what their personality is that day.