Coming from the NPD...
"As a property, Mario Kart is the all-time best-selling racing franchise in the U.S.”
There have certainly been other racing franchises over the years, many with multiple installments. Still, these little zippy go-karts manage to take the number one position. With how well Mario Kart 8 Deluxe is selling, it seems like that record is destined to continue on for quite some time!