Rocket steelheads seem to win most every penetration test they are included in. Balistic gelatin, plywood whatever...they either win, or are right at the top.
Steelforce heads should also be a top performer. The large blades allow a lot of friction if shot into bone, but as long as the arrow goes where it should, I can't think of a head that cuts deer hide better.
Slick Tricks are also a great head. AWESOME penetration, AND flight. There is SOME question about deflection....but MOST have no problems with this head.
Muzzy are a stand by. They do everything well
NAP shockwaves are suprizingly good as well. Costing less than NAP Spitfires, they open faster, and penetrate bone better.
I have no experiance with thunder heads...but they sound like a reliable head as well....same with WASP SST