I like and own:
http://www.amazon.com/gp/aw/d/B00ELMXZSC?vs=1
http://www.amazon.com/gp/aw/d/B00FEQ429U/ref=pd_aw_sbs_2?pi=AC_SX230_QL60
The first one is very protective without adding too much bulk. The second is very slim and is my 'daily driver'.
I'm using the Diztronic Matte Back Black Flexible TPU Case. I've really been happy for this case! It's sturdy, feels good in the hand, and it's not overly huge! Also, It looks good!