I just picked up this -
CapsuleRebel For iPhone 4 / iPhone 4S - SwitchEasy.
This is my first iPhone - so I can't really compare it to much - although I did visit BB and glance at their selection. Unfortunately - they won't mix and match the outer and inner colors - so I actually ordered 2 (black and white) so I could have a black spine against a white background which goes nicely with the white iPhone. I guess on the plus side - I now have a backup case that has a white spine against a black background.
Overall - I like the case. It's a very tight fit - feels well made and I think it will offer a fair amount of protection - but I'll leave that to others to test. It also comes with quite a few accessories - pretty much anything you'll need - including screen protectors.
My only con is that I'd like the inner piece to have more of a rubbery feel - something with a higher coefficient of friction to provide a little better grip on the phone. The plus side is it slides in and out of a pocket with ease - but it also feels like it could slide out of my hand just as easily.
Here are a few pics.
Sorry about the shallow DOF - wasn't really paying much attention.