Mind if I jump in here. I do like the Nats, but, theres no doubt that Carlisle is a much better show. Unless you are specifically going for the racing, Carlisle is a better show. Carlisle has more vendors, more show cars (but not so many race cars), more variety of show cars, more cars for sale, more special vehicle displays, and more. The Nationals was the greatest Mopar show on the planet (despite all its disorganized faults), but those days have long past. I started going to the Nats in 1985, and went every year for a long time. Now I go to the Nats every few years and go to the Carlisle show every year. I went to the Nats last year and again say Carlisle is the better show.
As a second favorite show, I like Spring Fling in California better than the Nats even though the Nats is a much larger show. For several years, my friends and I gave up the Nats and flew to LA for Spring Fling instead. Thats our plan for 2012. This year the plan is to fly down to Florida for the Gartlits Museum show instead of attending the Nats.