I haven't tried Ohio Valley pizza as I avoid most of the Midwest like a plague (I've spent substantially more time in the Left Coast, Southwest and even Mountain West than I have in traditional Big Ten country (ie not including Pennsylvania and Maryland)), but the description of it sounds absolutely horrifying. The description and pictures look like the ready to order Costco and Walmart pizza BEFORE they are cooked.
As far as worst pizza that I've actually had, hands down it is true St. Louis style with the absolutely revolting Provel processed "cheese". For those who haven't had it, it's essentially a saltine with ketchup and a slice of American "cheese food". And swapping out the Provel for actual mozzerella only lessens the pain, the other huge problem is the sickeningly sweet and ketchupy tomato sauce that they use.
Two other style I really dislike are Punxsutawney Style (which is essentially St Louis style with mozzerella ie cracker thin and crisp but with a sickening sweet sauce that tastes like ketchup) and Old Forge style (which is essentially Punxsutawney style but a little thicker and done in a rectangular tray like school pizza rather than a normal pizza round).
So far, those three (plus the thought of Ohio Valley Pizza) are the only styles I've had that I strongly dislike. All of the other styles I've tried have been decent to amazing. I'll list the styles I've had separately when I have more time.
