Got my Amzer Silicon case on yesterday and I'm liking it, has the thickened corners and the textured edges fit the hand real nice. I'm sure that everyone else has noticed that the earpiece area has that sharp edge at the very top of the phone; that problem is fixed with this case. And it's not slimy feeling like that Silicon case from Sprint for my Instinct.
IMO pay a little extra and get quality.
Amazon.com: Seidio Innocase Active Case for HTC EVO 4G - Limited Edition: Cell Phones & Service