OtterBox Pixel Cases
Another brand that needs no introduction is Otterbox. Any case they sell we can recommend without hesitation. The company's popular Commuter series is available for both of Google's phones, in addition to the Defender series. These are a little bulkier than many others on the market, but for a reason.
That reason being safety and durability. They make their cases thicker than most to make sure your smartphone is always safe from drops and accidents. These are expensive cases, but you get what you pay for.