SteelSeries' Arctis 1 Wireless ($100) was developed with the Switch in mind, so you can rest assured it'll work without any issues. Its custom wireless adapter offers better sound than Bluetooth, and you can also connect it to gaming PCs or Android phones.
While you might be tempted to pick up a portable Switch dock as a gift, we recommend not doing that. Since the console's launch, Switch owners have reported that third-party docks sometimes brick their systems. While not everyone sees those issues, it's widespread enough that it's simply not worth tempting fate. You don't want someone to blame you for killing their Switch, right? Nintendo's official Switch dock is still the best option for connecting the system to your TV, but good luck finding one. They're rarely in stock, and when they do show up, they're either refurbished or very expensive, like this Amazon listing ($98). (Note: The Switch Lite can't output video from any docks.)
A small USB-C power adapter like Anker's ($37) is a far better gift option, since there's less of a chance it'll kill your recipient's console. Power is a tricky thing these days, but in our experience Anker's devices are pretty trustworthy. This adapter can also be used to charge up USB-C laptops and tablets, so it's a useful tool for any geek's arsenal. For gaming on the go, Anker's PowerCore 10000 PD battery pack ($46) can fully recharge the console twice.
While the Switch supports cartridges, it's far more convenient to download games to a microSD card. Most generic cards will work with the system, but Samsung's EVO Select line offers a good balance of speed, reliability and affordability. We recommend going as big as you can: The 512GB version ($78) will keep Switch owners satisfied for some time, while the 256GB card ($38) might make more sense for casual players.
There's a good chance most Switch owners will already have a case they like, but even they'd welcome something like the Hestia Goods case ($10). It has enough room to fit the Switch or Switch Lite along with a few games and other accessories. For something a bit sleeker, there's TomToc's slim Switch ($20) and Switch Lite ($19) cases. Nintendo's official Switch Lite case ($20) is a great option too, and it also comes with a screen protector.