Now that the Long Great Lance is gone I would like to see the Great Lance's thrust come back. It is now more dangerous than ever to be a horseman with 2H and Polearms being able to rear your horse. If archery wasn't perceived as being shitty most of the cavalry you would see would probably be horse archers.
Polearms dance in and out of the couch lance due to the lowered speed and maneuverability of the horses, 7 in riding is pretty much mandatory unless you only fight other cavs.
Horsemen can't fight 1v1 against much, which is why people complain all the time about being horse bumped in a duel or having their kills stolen. Cavalry are the vultures of the battlefield, hoping to strike at those too busy to realize there is a horse galloping at their head.
The thrust would go a long way to bringing a headfirst charge back.