your hands and feet even. with sensory nodes attached to all of your joints, like a suit you would put on and you could see yourself on the screen at like a high angle like this
and other angles like almost first person like this
i understand grappling would be impossible and they may have to tweak the controls and angles when your fighter gets hit but this type of game is long overdue IMO and would be EXCELLENT for the fitness enthusiast
can you imagine standing in your living room fighting people online, imagine the workout, imagine the fun that would be! imagine the bragging rights of your speed and agility all the while keeping in your teeth and not getting a black eye!