1. Otterbox Preserver Edition
Otterbox is already known for their super durable phone cases, and now they've upped their game with a highly protective case that's also completely waterproof. (Well, it can be submerged in six feet of water for 30 minutes.) The two-piece Preserver model also protects again dust, drops, and screen-shattering. The case is slim enough to fit in your pocket and it comes with an adjustable lanyard so you can ensure that it's with you at all times.
The Otterbox Preserver Case, which retails for $90, is only available for the Samsung Galaxy 35, but it should be available for other phone models soon.