The good news is the EVA Travel Case, made by CTA Digital, comes with a mesh pocket for all your games, your console, as well as your accessories and features elastic wrist straps you can use to secure your 3DS for reliable on the fly protection
Speaking of protection, the black Silicone Protector, officially licensed by Nintendo, gives you a more comfortable grip as it protects the outside part of your Nintendo 3DS from dust, dirt, scratches and other common wear and tear culprits you'd like to avoid happening to your system.
You will want to make sure whoever you buy it for is over three years old though because some of the working parts are small enough to present a choking danger to toddlers or babies.
One cool thing about the Silicone Protector is you can still play your 3DS while it's attached! And it can be stored in either the Compact Case or HORI's Nintendo 3DS Hard Pouch because it's been designed to compatibly allow game play while inside either.
Now while we're on the subject of other cases you can use with each other that still allow you access to play while they protect, limit natural wear and tear to a bare minimum and prolong the life and value of your Nintendo 3DS system, (even with a more active lifestyle,) you need to consider the Metal Case (also made by CTA Digital) which some find more stylish.
All style aside though, the metal case, in addition to being scratch resistant, protects your 3DS from damage if you drop it. This doesn't totally eliminate damage from drops, but reduces it considerably.
(And even with the metal case snugly snapped around your system, you still have full access to all the openings, ports, cameras and touch screen!)
Not to be passed over, the Compact Case, also licensed by Nintendo officially, is designed to work with your silicone protector and HORI's protector attached and stores your stylus, 3DS system and has pockets for up to 3 Nintendo 3DS game cards to boot.
It's important to note your purchase of your Nintendo 3DS is an investment worthy of protecting so these cases and protectors help extend your enjoyment and the life of your Nintendo 3DS much longer that without them. Nothing is worse than looking at a system ruined when it can be avoided simply by securing your 3DS with the protective accessories designed to keep it from harm's way.