Hardware:
Switch - 22.80 million (keep in mind initial shipments of the Fortnite bundle are certainly counted here as it has to be shipped out by that point despite only releasing a week later)
3DS - 73.80 million
Software - Switch:
Super Mario Odyssey - 12 million
Mario Kart 8 Deluxe - 11.8 million
Breath of the Wild - 10.10 million
Splatoon 2 - 7.45 million
1-2-Switch - 2.70 million
Kirby Star Allies - 2.25 million
ARMS - 2.20 million
Mario Tennis Aces - 1.85 million
DKC: Tropical Freeze - 1.75 million
Xenoblade Chronicles 2 - 1.55 million
Bonus (probably in a press release and/or investor's Q&A):
Octopath Traveller: 1.8 million
Fortnite: 3M+
Paladins: 500K+
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454 List as Google Doc: https://docs.google.com/spreadsheets/d/1aW2hXQT1TheElVS7z-F3pP-7nbqdrDqWNTxl6JoJWBY/edit?usp=sharing
The Steam/GOG key gifting thread: https://gamrconnect.vgchartz.com/thread/242024/the-steamgog-key-gifting-thread/1/
Free Pc Games thread: https://gamrconnect.vgchartz.com/thread/248138/free-pc-games/1/
