Well, I think it's all about where you grow up, and what kind of pizza you grew up eating.
I grew up in the Tulsa area of OK. Mazzio's (and Ken's, same company, really) is really big here. That's what I grew up eating, and what I prefer. I like their sauce. Most of their crusts are fine, be it thick, thin, medium, etc.
I've never been a really big fan of Domino's, although that's what PeppA usually orders. When we lived in Jackson, MI, for a few years (that's where she's from), she also liked Andy's Pizza. I wasn't that impressed with it. All toppings on top of the cheese, on a medium whole-wheat crust. It was really hard for me to get a decent "bite" out of it without resorting to a fork. The taste was OK.
I'm not a big fan of Poppa John's either. Pizza Hut is OK, but greasy. I haven't had Little Caesar's in a long time. Simple Simon's used to be the big "cheap" pizzeria chain here, but they've largely gone the way of the Doe-doe. My family, and some friends, have told me of a new locally-owned chain called "Cheesy's", which is supposedly rather good, and, dirt-cheap. I haven't tried them yet, so I don't know for sure.