It would take a huge amount of storage to have the maps saved on the phone so that it would work without using data, I'm not sure I've ever seen a navigation app that would accomplish this, although I've found a topo map app that does.
Garmin or Navigon...both owned by Garmin. I personally like Garmin because that is what I am used to. But beware...these will eat at least 2GB of storage.
In all honesty I've used the Apple Maps app in two different major cities and their surrounding areas and haven't had a problem. I know problems exist but if I'm ever going somewhere I'm totally unfamiliar with, I usually take a hard copy of the map as well, or at the very least screen-capture the route if possible.
The Google Maps app is also available now too and pretty reasonable.
Thanks for the responses guys! I like the apple maps for when i'm near civilization, but this time I am looking for something for when im way outside civilization, where i can enter GPS coordinates, etc.
Did you even look at MotionX apps? I don't know what you're hoping to find but their 2 apps fill any GPS need I have. I'm assuming the iPhone and iPad are basically the same when it coes to these apps.
Motion x gps here!, I downloaded the topographical maps for 100 mile radius where I offroad, leaves great trail markings with alt/speed/distance, etc. logs...