Dick's gets plenty of praise, so I don't have much to add that hasn't already been said below. But I wanted to mention that their pizza is surprisingly good. My last two visits I've had the #3 pizza (mexican sausage, onions, mozzarella) and it's been great.
My last time there, we actually tried to get a booth at Richardson's--it was full, but the hostess was nice enough to call over to Dick's and get us in at their last free table.