I voted for MMA, Kickbox, Bootcamp. I hate step, plus she has tons of step workouts already, so I'd like to see something different. I don't have the space the step workouts require either. I'd like to see something that is really high-intensity without the high-impact or torque or knee pain inducing things that come with the step and jump-around workouts. Hence - kickboxing or bootcamp style.
Kettlebells seems interesting, but I'm kind of maxing out on equipment at this point, so don't really want anything that necessitates more.