As a mutant slave Costco shopper, I get sucked into buying a slice of their pizza occasionally, and while at $2 for a giant slice, it is a good value, it just never tasted all that good, and as a native Chicagoan living in SoCal, I am always on the quest for good pizza.
That being said, I bought one of their prepared, uncooked 3-cheese pizzas today and brought it home. This is essentially the same pizza that goes in the Costco ovens for $1.95 a slice (1/6 of a pizza I think) or $9.95 whole. The Costco cooked pizzas are a bit greasy and just not cooked enough, but if you ask the for a well done slice, I 've had the cheese burnt beyond edibility.
Uncooked it's $7.99, a real bargain. I heated up a large pizza stone for 30 minutes at 500 degrees and put the pizza on it, dropping the temp to 400. 10 minutes or so later, i pulled out a pizza that was MUCH better looking and tasting than the cooked version served at Costco. The crust was crisper and less oily and the plentfiful cheese had just started to brown and get a "crust" to it. A very good pizza and a great value to boot.