What's your opinions? My vote goes to the Griffin Survivor, OtterBox Defender 2nd, Trident Kraken 3rd and Ballistic HC 4th.
Honestly, it depends on what you're looking for. I only have experience withe the Defender, Survivor, and Kraken.
I think it comes between Otterbox and Survivor
Survivor definately has the most protection of the 2, but at the cost of functionality. Don't get it if you use the camera a lot. Also, if you have big hands (like me), it will probably be difficult for you to type letters on the edges. The survivor also has more protection for all of the ports.
I have both of them, but recently switched back to the Survivor because the flap near the dock connecter was really pissing me off on the Defender (wouldn't stay down), and the silicone was getting all loose.
If the Survivor could fix the camera flap issue, and maybe reduce the bulk of the silicone by 15-25%, I think it might be the perfect case.
Seidio Rugged. It actually makes the Otterbox look skinny.