I've been using the Brando Aluminium Case and have been very happy with it (see
This Thread Here). It certainly isn't perfect, but I've yet to find a case for any device that is. Ideally it should offer perfect protection in all circumstances, access to all functions without the need to remove from the case and add virtually no weight or bulk to the device.
But that ain't gonna happen so you have to weigh up how much protection you are going to need with how much extra weight/bulk you can put up with and how much access you require without removing the case.
The Brando Aluminium offers absolute protection for the device (as I demonstrated in the link above
) and offers access to all the functions (including the keyboard). It doesn't weigh much but it does add fairly considerable bulk and, to most people's eyes, looks pretty ugly.
Personally, I like the combination of the Aluminium case when I'm out and about in areas where it could get seriously damaged, and something like the proporta book case or the Krussel Cabriolet when protection isn't so important and I just want something that will protect from scratches but is comfy to carry about with me.