I personally would love a new F-Zero game, some of the new sonic levels remind me of fzero and how fun that would be if they did it right.
I would also like to see a GOOD mario kart game, in the footsteps of snes mario kart.
MOST OF ALL...
I would like a light gun game compilation BY SEGA... i want the entire virtua cop series and the entire house of the dead series put in compilations and sold for the wii. That would just be a spectacular dream come true right there.