The water shooting in mario sunshine is the greatest gimmick mechanic in any game ever made. That it happens to be in the least polished 3D Mario might make Sunshine a more unassuming title to the less fully acquainted, the fact is that this game is an attempt to one up the greatest game ever made. It succeeded, mostly.
Future Mario titles attempt at similar, more subdued, and inferior movement gimmicks on top of superior, full Nintendo polish that have to more than make up for lacking Sunshine's water and ambition to compete.
Galaxy and Odyssey are more immaculate games that nevertheless shoot for slightly lower perfection that Mario 64 attained and Sunshine tried for.