I picked up a Samsung Galaxy Nexus directly from Google the day they started selling it. I never used a case with my G1 since it had a keyboard and the case had a nice matte coating that made the phone easy to hold on to. The GN is thinner and lighter which makes it a bit harder to hold on to so I looked for a case that would give me a better grip on the phone without much bulk and protect against bumps and drops.
The Diztronic Matte Back Translucent Smoke Flexible *Revision 3* TPU Case was exactly what I was looking for and only $9 to boot.
Looks: I went with the translucent Smoke colored case so you could still see the Google logo on the back and it is fairly close to the color of the back and side panels. I think it looks great and the solid black case would probably look just as good.
Grip: I can actually use the Galaxy Nexus one handed now without risking a drop. The sides of the phone are fairly slick and had it almost slip from my hands a few times in the first week. The rubber on the case definitely adds grip and just gives you a more solid hold on the phone.
Pocketability: The case does not add very much bulk and it still fits nicely in a front pocket. The GN is pretty thin to begin with so I didn’t mind a bit of thickness added to it.
Protection: The case creates a little lip around the edge of the screen which helps keep it safe when placed face down on a surface. In a fall it should help protect from damage, but I wouldn’t trust any case to fully protect a phone from a hard fall.
Verdict: Buy it. If you are looking for a case for your Galaxy Nexus I highly this Diztronic which is a steal for $9.