Easily Wii Sports. It was a cultural phenomenon, and I personally had a lot of enjoyment with these games too.
The "new" thing I liked even more this century was Advance Wars, but that IP technically existed in Japan in the 20th century. To me and other North Americans it was new IP, and it's in my top 10 games of all time.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox