There are two HUGE accessories that Best Buy is missing out on a lot of money on in terms of attaching additional revenue to Apple TVs. Stocking these accessories in every store, would be a good start. Educating employees on what they are and why they're important would ensure a strong finish (and attach).
The USB-C cable is the only way for the new Apple TV to interface with a computer for things like taking screenshots of screen recordings from the device and more importantly restoring the device to factory settings via iTunes (in the event that over-the-air restore doesn’t work). I've actually had several people coming in store looking for these and only one store in this market stocks them (out of 8). A quick online search reveled that a major office store chain carries this in EVERY store and all 18 stores in this market has them in-stock today. You don't have to read too far into that to see the opportunity. Translation: every store that sells the new Apple TV should stock this, if not every other store.
SteelSeries Nimbus Wireless Gaming Controller (Not found on BestBuy.com).
One of the first Apple-TV-compatible gaming controller available on the market currently. The SteelSeries Nimbus wireless controller lets you play hundreds of your favorite controller-supported games on your new Apple TV, iPhone, iPad, or iPod touch. This full-sized controller's ergonomic design is perfect for gaming. It gives you 40-plus hours of game play with just a quick charge using the Lightning connector, along with LED notifications, an easy-to-navigate menu button, and pressure-sensitive buttons for the most precise gaming controls. Interestingly enough, the Amazon Fire Gaming Controller is at least avaialble online (no availability in any store nearby) but this Nimbus is nowhere to be found. Both retail stores from a certain big fruit company have this in-stock.