well I personally do not like bumper one...I just picked one picture from the iphone case website ( recently found and cool one). Don't know whether you like it though...this is heavy taste. haha- I don't buy this one - - not my type.
I have recently purchased two Otterbox Defender cases (one for my wife and one for me) for our iPhone 4.. We are very happy with the cases. They have a good fit and feel. It provides a nice protective enclosure. We did go with a Zagg screen shield though.
We are not so pleased with the clip-holster. The clip is very uncomfortable.It digs into the side of the waist. We are also concerned the iPhone might pull away from the holster. I have been looking for an alternative holster that would be compatible with the Defender case with no results.
The otterbox commuter is a great case. I've had the otterbox defender as well which I just found it was too bulky for me. The commuter is pretty thin and is easier to slide in and out of your pocket vs the defender. I've dropped my phone from 5 ft. two times on the concrete and my iPhone 4 has survived unscathed both times. Hope this helps!
I bought the Griffin Technology Survivor the day I bought my iPhone. It's a little too much case. It's bulky, especially in your pocket. Also, the audio jack input only allows thin apple-like jacks to go in.
I really like the case, and feel really confident with its level of protection.
I do want a slimmer case, I might check out the new Explorer case from Griffin.