As an East Coaster, I will agree that In-N-Out is better than Five Guys. The bottom-line with Five Guys is that their quality control is spotty. An excellent burger in one location unfortunately has to compete with a forgettable burger experience elsewhere.
I believe that Shake Shack (NYC, MIA, DC) has both those joints licked. Shake Shack is always spot on, and always produced with high grade ingredients. The rest of the country that has not been to a Shake Shack should make a trip.