For the uber-paranoid (or, more likely, uber-active), Urban Armor Gear’s Monarch case is probably the closest you can come to guaranteeing the safety of your S8.
The toughest of the company’s impressive protective range, the Monarch boasts what it calls five layer protection: an armour frame, top-grain leather, a polycarbonate plate, alloy metal, and impact-resistant rubber.
In practice, what that means is that the Monarch feels tough. Solid. Sturdy. Nothing’s getting through here.
The only downsides are that it doesn’t offer any additional protection for the screen, beyond the raised edges, and the aesthetic is, well, functional – and only available in one colour, graphite.
The availability for the S8 (non-Plus) version is limited, but US shoppers can find it on Amazon for around $23 (it ships to the UK for an additional US$12). The rest of Urban Armour Gear’s range comes in a few more colours, with almost as much protective power.