Incase do one that I picked up when getting the iPhone from an Apple store. You can see it on the Apple web site. It is working out quite well - my iPhone remains in mint condition (aside from the odd transient fingerprint). Could really use a case that has someplace to stash the cleaning cloth and bluetooth earpiece though...
I've broke two Marware hard cases. The clip is useless, if you sit down against something it snaps the weak plastic stubs instantly. After looking around I said sc#W@# it and I took apart an old hip case's clip and epoxied the clip to the marware case. It's never coming off now. You wonder who designs these cases, a bunch of idiots.