otterbox defender case for me. i work in a rough environment so it works perfect for me to protect the phone. the only thing i did was not use the included screen/keyboard protector as it made the screen too blurry and the keyboard too awkward to type on. i replaced the screen protector with a zagg invisible shield.
i have the sedio innocase crystal but its sitting in my car atm cause i have a ProClip cradle in my car and its a PITA to keep taking it off so im going with no case for now. But i have an att holster cause ive broken 2 OEM Holsters and they dont have a warranty and the ATT one has a 1 year warranty so im using that for now.
otterbox impact silicone case but i just got this weird plastic snap on case that clips on the sides of the phone that i sell at the cell phone accessory store i work for that im testing out.