bumper/case

If you want ultimate protection, definitely go for the Otterbox Defender.
Although it may not look the prettiest, it does indeed provide absolute protection for your phone.

If you want to go for the metal cases, there are issues to look out for which is the reception issues.
Also, they may look really good on the phone, but provides little protection if you require shock protection.

There really isnt a case out there that's the best in all criteria, but obviously, everyone has their own opinion.

Good luck finding a case of your choice!

 

Speck Candyshell or Otterbox Commuter look ok and offer decent protection.

 

I recommend Scosche bandEdge cases. It was the first case that I got for my iPhone 4.
http://www.igadgetsmall.com/iphone-4-case-scosche-bandedge-black-black.html

Also, take a look at the CandyShell by Speck and the Feather by Incipio.
Both of those are great cases.