Mine would be a Partridge rock with awesome feathered feet, beards, muffs...a humongo comb if it was a roo...and eggs that are always fertile..and it goes broody when I say so.
My ultimate chicken would be a giant Salmon Faverolle-esque rooster the size of a Black Jersey Giant, with a huge single comb and clean wattles and feathered legs and feet. His sickles and saddle feathers would drag behind him like a Phoenix roo's. He would be extremely large, fluffy, and very, very friendly. He would have the classic rooster crow.