If you are searching for the toughest protection in the world for your precious iPhone 3G or 3GS, look no further than the Otterbox Defender series cases (also available for iPods, iPod Touch, BlackBerry, Samsung phones). This monster of a case is menacing just by looking at it! The case itself w/o the belt clip (included) is almost 1" in thickness (0.8" to be precise). Take a look at the comparison photo I took showcasing its bulk next to the Griffin Outfit case (left) I reviewed yesterday, this thing is not kidding around.
Construction: All that thickness didn't come without a reason; the case comes with in total three components with four pieces of parts. The inner hard-shell case is composed of two halves (front bezel and back casing) which provides a very strong foundation for your iPhone; it even includes a built in LCD protector that doesn't need to be applied separately. The outer rubberized case adds more protection and acts as a reinforcer to hold the inner casing together snugly as well as plug out just about every port on the phone. Finally there is a polycarbonate belt clip which tops the entire package off. The end result is a massive case that is ruggedized for a very active person.
User feedback: With your iPhone 3G or 3GS enclosed in the Otterbox Defender, it looks like it belongs right next to a Panasonic Toughbook riding inside a military spec Humvee. The sheer size of this case is impressive not to mention how solid your iPhone feels in your palm. For some reason, I don't feel like the ladies would be drawn to this case and for that matter, the added thickness may not chime well with urban/artistic types. If you are a hardcore traveler or take your iPhone outdoors in some tough terrains, I can see this case paying dividends.
Conclusion: Overall, the Otterbox Defender case is built with high quality engineering and is probably the toughest protection available to date. At $49 MSRP (Amazon $29), this case is here to serve the needs of people who demand the highest form of protection to their prized iPhone. If you want a solid case without going to this level of committment, checkout Otterbox's new Commuter series (my review here).