If you are talking about chains 2 bros is the best for me. Only a NYC chain but their $1 slice deal and NY taste put it at the top of my list.
For the west coast it's a tie between Round Table and Mountain Mikes for me. Both have great skins, killer sauce, and quality toppings that are hard to beat.
As for larger more "mainstream" chains. I think Cosco wins for its combination of cheap, tasty, and huge, though not a dedicated parlor.
Otherwise Caeser's gets the job done. Especially with it's hot n ready promo.
Honestly I just wanted to use this excuse to post pizza pics.... I realized while working at a parlor over a decade ago that it's the one food I can never tire of.