As far as iPhone cases go: I like them to not add bulk and just protect from scratches. Specifically I like them to protect the phone back from getting scratched when put on a table, desk, or else. The beauty of the iPhone is it’s sleek design, adding a clunky case negates that. The other thing I like in a case is some grip (not as much grip as a silicone skin, too difficult to get out of your pocket when driving) but enough grip to keep it from sliding off your leg if balanced on your leg while driving. I’ve found 2 that are winners in that fashion.
Moshi iGlaze 3G:
Recommended by a friend this case is by far the best. All important buttons are easy to access especially the ring/silent toggle. It’s slim and doesn’t add any bulk to your phone. There is a cutout to show the apple logo: I know it’s brandishly ridiculous but that in my opinion is part of the beauty of the phone. The Moshi case includes both a screen protector, and little circle to protect the apple logo. It’s grippy, but not too grippy. This case is the best so far by my criteria (see above). It’s also only just over $20. Making it a clear winner.
Power Support Air Jacket:
The black case was my fav for the last year+. Recently got a clear one and it’s great, but it doesn’t have the slight grippy feel of the black jacket and is a bit slippery. The Black case was good but not totally what I wanted. I scratched the covering off my black case to reveal the apple logo, worked ok, but it was a bit barbaric. As stated above I know it’s ridiculous, but part of the beauty of the phone (see above). My only complaint was that the case did make toggling the ring/silent switch a bit difficult. Everything else was great. These cases are around $35.