I tried an otterbox commuter case and it was junk. It failed within a week of putting it on the Torch. I could not believe that I spent so much on it...
Last month I decided to try again to get something that was durable and bought the following on eBay for $5.49 with free shipping.
Black Rubber Hard Cover Case for BLACKBERRY TORCH 9800 - eBay (item 160550131109 end time Feb-23-11 07:31:02 PST)
So far it is working out great. The front screen surround on the slide is staying in place. And it looks good, too....