For me, Rosalina has always been really common while Daisy was on the same level as DK and Wario. Seems to be the opposite for other posters for those two. --- http://www.youtube.com/watch?v=eStcSpAdodc&feature=plcp <- I didn't make the video, I just agree with it.
VERY COMMON * Metal Mario * Shy Guy * Toad + Lakitu * Koopa Troopa * Miis
COMMON + Yoshi * Rosalina
SOMEWHAT COMMON +Daisy * Luigi * Peach
RARE * Wario [get it? wario rare] * Honey Queen * Donkey Kong * Wiggler + Mario
VERY RARE + Bowser [rarer than honey queen. IF you all check out battle mode, there is almost always a honey queen there. incorporate both race and battle equally and honey queen isn't too rare. although i think people use honey queen in battle about 10x more than in races]