Just Dance 3

The game will award one of seven different “Style” awards after every song at the bottom of the ranking screen.

According to the manual:
Twins: Two players danced the same way
In Rhythm: You had the best sense of Rhythm
Creative: You have your own style
Energetic: You put the most energy into your moves
Smooth: You danced well without breaking a sweat
Wild: You shook around the most
Lazy: You were the least energetic… try a little harder

You can obtain all of the last six with one Move Controller, but the first requires two. They seem to mostly come at random, but if you dance different songs it is easier to get different styles. Slower songs give "Lazy" more often and fast ones tend to give out "Wild" or "Energetic." "Smooth" will come if the dance is almost perfect. In Rhythm requires that the movements you make match up with the beat of the song really well.

If you are short one style, Twins can be earned fairly easily by holding two Move Controllers in the same hand and playing a song.