I grew up in Arlington and still have family there. And each time I visit, it includes an order to Mr. Jim's. I am not sure what makes it great. It doesn't fall into an regional description (i.e. Chicago or New York-style). It is just great pizza that takes the best from all regions and tosses it out into one delicious pie.
Pros: great coupons, prompt delivery
Cons: not great for dine in