Which style would be the best for Mario's Wii U/HD debut?
My personal preference would be in the open world style of Sunshine but with slightly larger levels and a hub world probably double the size. Nintendo's mario games look absolutely amazing and exploration is one of the best parts of their games, however, the exploration was extremely limited in Galaxy, it was a little better in 3D land but still not great. I would love to see something more along the lines of Sunshine.
On a side note I would also love HD remakes of both SM64 and Sunshine.