Right now I'm using the Speck Candyshell with a Steinheil ultra crystal (I think) screen protector. I cn honestly say that out off all the cases I've used on all the phones I've owned, it seriously is amazing. Best one I've ever used. I always had an issue with dust, dirt, lint, or whatever else getting into my cases. So I started cleaning them every day. Well with this case, it's not an issue one bit!! It's a hybrid case. So it has a rock hard outer shell, with a nice hard silicone inside. The corners are almost "split" So if you drop it, the silicone will absorb all of the impact. Also, the edges on the front around the screen are all that same hard silicone. Couple it with a good seen protector and your good to go!!
Since its a hybrid case it doesn't add much thickness to the phone at all. It's amazing. Buttons all work perfect too.
It might be on the the expensive side, and a b*tch to get on and off at first... But it is WELL worth it!
Sent from my HTC One X on CM10!