Re: How about a screen that doesn't crack?
You don't need an enormous case. You need a good case.
I had such a good, non-large (indeed, it was very form-fitting) case on my old iPhone. I dropped it and stepped on it a zillion times. Nary a scratch.
It took DROPPING THE PHONE THREE STORIES ONTO A HARD SURFACE to damage it -- and even then, the screen was not even scratched (let alone cracked or shattered). All that happened was the screen and the home button popped out a little bit. I got it repaired that same day.
(Alas, the antenna was permanently screwed up, and I wound up getting a new phone a few months later, but the glass was fine.)