Pikmin or Animal Crossing
Both of these franchises were introduced worldwide during the Gamecube era. While Nintendo attempted to create many new IP's during this time, only these 2 were successful enough to survive. The question is, which do you personally like more?
I personally think very highly of both franchises and consider them 2 of Nintendo's best. In the end, I enjoy Animal Crossing a good bit more. It's fun and relaxing gameplay just can't be found anywhere else IMO.