I bought the black silicon cover that has the rubber texture. I like that over the clear case because it looks better and it gives me a better grip of the phone.
It completely covers up the power button and the volume rocker button, but provides a raise hump over those buttons. It helps me to find the power button much easier than before because it is raised.
@burningembers, you might have gone to the wrong store. The one I went to has many covers and cases.