You can't compare it to burger joints in different regions. I like In n' Out better than Five Guys, but I can't exactly fly to CA to get my burger fix. Five Guys is the best fast food burger in their respective locations.
In-N-Out's deducation to quality and top-notch customer service is actually quite similar to Five Guys. The reason they're only in the Southwestern US is to ensure that each restaurant is close to a food distribution center. That way all their food is made with the freshest ingredients. They've been family-owned and operated since the 50's.