The Apatow crew aren't part of the Frat Pack. The original FP members are Ben Stiller, Vince Vaughn, Will Ferrell, Steve Carell, Jack Black and Owen and Luke Wilson.
https://en.wikipedia.org/wiki/Frat_Pack
The Apatow crew (Seth Rogen, Jonah Hill, James Franco, Jason Segel, Paul Rudd) were referred to as the 2nd generation or something.
Anyway, I'd rank the films above:
Top tier: Wedding Crashers, Old School, Superbad
Mid tier: Dodgeball, Knocked Up, Step Brothers
Bottom tier: This Is The End
Haven't seen Anchorman and The Internship.