I tried a number of cases. To my opinion the best compromise in between bulk, protection and price is this one:
TPU Gel Silicone
I was surprised about the good quality for the price. In particular the operation of the (covered) main button and volume rocker is pleasant. Other phones have cut-outs on this spots, so I had to poke inside for reaching the button. It adds considerable weight to the phone, which does not feels as elegant, slim and trim anymore. Avoid the white version, it can look dirty easily.
This one is also good with even slightly better protection, but it's not quite as accurate cut:
I don't want to mention them all, just one more: My biggest disappointed was the Nilkin
case. Now some people will shout out bcs they like it so much. It is to my opinion just a scratch protector. I disliked the slippery material. I had a couple of situations when the phone almost dropped down when I operated it 1-handed, and this case is nothing more than a really thin layer of hard plastic. Well, it does not add to the bulk and looks good.
All these cases are also available from other Ebay vendors.
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