I had an otter box on my 3GS had that phone 3 years, before that I was going thru phones every 2-3 months. I now have one on my 5 and still not disappointed, dropped it in the toilet soon after I got it phones still good. Also they stand behind their product the flap on the charging port on my gf's phone wouldn't stay shut she followed the directions on their site and the sent her a new part free.
Be carful buying the cheaper ones , they are most Likely knock offs