Best with mashed taters, Yorkshire Pudding, and plenty of horseradish. Maybe some vegetables for the health nuts, but I would never waste my appetite on them with something this tasty to enjoy.
Effortless method at Youtube - How to cook Perfect Prime Rib
Rule of thumb is 1 lb of meat per person, so it's difficult to make for over 8-9 people, really, without a commercial oven. That's why people make filet instead of prime rib for parties and have their prime rib in restaurants - but I think most people prefer a prime rib (technically "choice," not "prime" and technically, as reader notes, "standing rib roast"). It's the perfect food for human beings, along with mashed potatoes.