According to Nikkei Asia, Nintendo may be producing as many as 30 million Switch consoles this fiscal year. If all these units sell, the Nintendo Switch will be the fifth best-selling game console of all time with 110 million total units.
https://www.notebookcheck.net/Nintendo-may-produce-30-million-Switch-consoles-this-fiscal-year.536672.0.html
When it comes to 'best-selling consoles in history', I really wish someone made an estimate, how much NES sold in all version- that is including all the illegal clones. I know that half the world- all post- eastern block, as well as South America, played NES clones, and the total 'NES' console number must be much higher, than the official one.