RE: Happy Joe's & Harris Pizza
for my money, the real king of "Quad-Cities-style" pizza is Frank's pizza in Silvis, Illinois (and now Bettendorf).
Happy Joe's is an ok enough place -- but despite its idiosyncratic toppings (like Taco Pizza), it really isn't something new. It's just a typical midwest-style thin-crust (like in St. Louis or Chicago) pizza with unusual topping choices.
However, Frank's and Harris' pizza are an entirely different animal: their delicious, bread-like think crust pizza is similar to the thin crust pies made in NY and the east coast, but the way they cut their pies, and -- especially -- the way the sausage is appled in an even layer -- make them a unique style of pizza that I've never seen anywhere else in the U.S.
They really merit a visit from Jane & Michael -- and perhaps some investigation on how this style of pizza was born.