Speck makes a few different GS3 cases, including the Pixel Skin HD (pictured top right) and the popular CandyShell case, which you can see protecting plenty of iPhones. The CandyShell (pictured at bottom) comes in multiple colors and fits very snugly onto your phone. The inside is made of soft rubber, whereas the outer shell has a smooth plastic sheen that gives it a striking look.
While the list prices can be high on Speck's cases, you can usually find them for significantly less on Amazon. For instance, the CandyShell lists for $35, but can be had for closer to $20, depending on your color choice.