The true goal in the pizza business is to be cheapest, most convenient, and best quality all at once. Inevitable compromise has led to two potential options here for me.
I feel the current leader in value is Domino's. Their Mix-n-Match deal for 2 or more medium 2-topping pizzas makes their better pizza with more variety a significantly cheaper option than Little Caesar's. I desperately wish that Domino's had a breadstick or cheese stick option that wasn't a complete disappointment, but if you just want some good, cheap pizza, no major chain will give you a better option.
The traditional winner here is Little Caesar's. The $5 Hot-N-Ready pizza was a revolution for the industry, and they held their place for a long time. Sadly it's been a long time now since a $5 pizza was something you could have (and actually want).
Best frozen pizza
This one's tricky! The easy answer is the Red Baron Brick Oven Crust because it's my favorite overall frozen pizza, but it's not necessarily the best frozen pizza. The Totino's Party Pizza is incredibly cheap and surprisingly good, and often wins me over for the convenience of baking in a toaster oven. The Great Value frozen pizzas got a lot better a few years ago, and I particularly like the Rising Crust Pepperoni.
Best local dine-in pizza
I think the best overall pizza I've had was from Pizzeria Seven Twelve. An incredible crust, and all-around excellent.
Pizzeria Limone has very unique pizzas, many of which are surprisingly great. If you're looking for something a bit different, give it a try!
Two Jack's Pizza is also quite good, though I like their cheese sticks a lot more than the pizza.
Worst pizza
Don't eat gas station pizza that's been under a heatlamp for ~20 hours. I did, and I regret it.
Another truly terrible pizza was from a place I went as a kid called "Jungle Jim's". The venue was sort of like a Chuck-E-Cheese, but the food was genuinely inedible.