I'd be hard pressed to settle on a single favourite. Of course, the Spit, P51 and Mosquito are near the top of my list, along with others, but one that is in there somewhere is the B25 Mitchell. Not for any reasons to do with performance or ability in intended role, but for its looks. See one on the ground today, and remember when it was designed and built; it looks modern, with the tri-cycle gear, the rounded lines and smooth exterior, that is, with the Perspex nose. It just looks right and, as most engineers would say 'If it looks right, it probably IS right!'