I have tried them all!! All the big brands: otterbox, speck, casemate, etc..
A few things you need to know from MY experiences:
1. iPhone 4S requires a BIG camera hole on the case because of the improve sensor for camera, it needs a big hole to let in light. iPhone 4 can make do with a smaller camera hole, but i would just go with a 4S case just to be sure. In addition, a big camera hole helps avoid "flash washout".
2. Unless you go swimming or are around water, you probably don't need Lifeproof. Lifeproof is an excellent case, but it does decrease quality of sound such as thru earpiece. In addition, it has a a small camera hole...and a piece of glass (with anti-reflective coating) covering it. I am sure that it takes OK pics with the case on, but why take a risk of ruining picture? Again, if you're around water or really clumsy around water, then Lifeproof is your best choice.
3. Otterbox Defender case are excellent, but bulky. And the two that i have had creaks and groan after a while. And for those with Defender, i HIGHLY RECOMMEND getting rid of the attached screen protector (very easy to do)!! Instead, use another screen protector with it (such as Zagg HD or PowerSupport Crystal) along with the Defender case...trust me, you will thank me for it!
4. The TPU and silicone cases are nice, but not very protective if your phone flies out of your pocket and hit pavement glass first. (Trust me i know!) The problem is that the corners (esp corner where volume/headphone jack) peel back on impact...thus, exposing your screen. The same applies to Otterbox Commuter.
5. Slider cases are cool, but they get loose after a while (esp. if you take it off frequently) and leaves big gaps in the front. Otterbox slider has been known to scratch the metal ring around iPhone!
So, you may be asking...why did i finally end up with?
The case and holster combo that i have now is my favorite:
1. Case:
Amazon.com: Puregear Iphone 4 Hard Shell Case for Verizon & At&t: Cell Phones & Accessories
You can get this case on Ebay for $12:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
Why is this case good? It is a hard case...so, it will help protect for accidental drops. This case is not for you to kick or drop from high places. It is basically a 2-piece case AND a slider all in one. Unlike a slider case, the gaps are on the side of the phone, not the front. In addition, it is a slide-n-lock mechanism (not just a slider only)...so, it probably won't get loose over time. This case is NOT for someone who likes to take their case off frequently...it snaps on (two pieces come together) AND then slide to lock. It is NOT easy to take it off quickly. The corners of the case is slightly thicker for impact protection. But, again, this is NOT a soft case. This case, for me, represents the best of what i am looking for. It is slim yet protective enough for accidental drops.
BTW, this case is NO LONGER in production...so, i would buy one now just in case.
2. For the belt holster (which is a must have for me) for the case, i use this: Core Protective Gear....CRC91997 (UPC 004385962618), made by Body Glove. It is only $10 and fits most slim cases well. And it is cheap. See pic below for case.
Just my experience.
