Not sure what else you'd call the PAC12:
The Pac-12 was the first conference to win 500 team titles & currently (As of June 28, 2018) Pac-12 members have won 513 NCAA national championships, which is 215 more than the next closest conference, the Big Ten.
https://en.wikipedia.org/wiki/List_of_Pac-12_Conference_national_championships