I have been using the Otterbox case on my iPhone 4 for a few months. I really like the case and the protection it gives my phone. The case comes with a soft inner silicone sleeve that your phone fits inside. Then you put the hard plastic outer shell over the sleeve. The case is nice because it doesn’t add a lot of thickness and bulk to your phone. You can still put the phone in your pocket if you want to.
The one thing that gave me trouble was getting the outer hard shell over the inner silicone sleeve. It takes a bit of work but it will eventually form and the outer case will fit over and line up.
The Otterbox also comes with screen protector. This was a good screen protector and was fairly easy to install. It’s sometimes hard to get the protector lined up with the buttons and all the air bubbles out.
I do recommend the Otterbox products, I have great luck with them.