Diddy Kong racing was considerably good despite the fancy gimmicks of planes and hovercrafts, but back on topic:
MKDD was one of the good mario karts despite major changes within the item system (Which i'll admit it was only decent because of the special items), and I'll be honest they should bring back some of the items like the big banana and heart sheild
MKDS was decent but the item system was annoying if you were in first
MKWii is decent, but with the lack of free for all battle and the item system flaws caused it to be the weakest game play mechanics of all mario kart
MKDD was one of the good mario karts despite major changes within the item system (Which i'll admit it was only decent because of the special items), and I'll be honest they should bring back some of the items like the big banana and heart sheild
MKDS was decent but the item system was annoying if you were in first
MKWii is decent, but with the lack of free for all battle and the item system flaws caused it to be the weakest game play mechanics of all mario kart