I have been purchasing OtterBox's for my iPhone's for 6 years now. People are amazed when I throw my phone across a room to show them the durability of this product. I have never had a cracked screen on any of my phones. In my opinion go for the Commuter Series as it is more slimline and is less likley to break over time. Stay away from the defender. I have just purchased 2 more Commuter cases for the two new iPhones I just ordered.
Yes the screen protector may peel over time from contacting the rubber on the sides however I replace my screen protectors regularly so it's no biggie for me. Besides almost all of my friends screen protectors peel off over time no matter the brand of cover - dirt gets in and the peeling starts.