that's so hard, i'd have to say the color. after having it, it just is so much more awesome than all of the other versions. even though i love all the classics. :x
I chose music star 'cause it's like every tama join together with some new stuff it's got no antenna like v1 & v2 it's got jobs like v4 and mail like v4 it shows 3 charecters( only when you get married ) like V5 and a whole load off new stuff