The pilot reported that during landing and once established directly over the helipad, he proceeded to hover taxi over to the assigned landing location, but during touchdown the helicopter unexpectedly shifted forward, rotating onto the front skids, then began to oscillate. The crew heard a loud “bang” and subsequently the helicopter became airborne briefly before settling down hard on the pavement and the helicopter started to go into ground resonance, becoming uncontrollable. The pilot reported that the helipad was congested with several other aircraft on the ground and two preparing to land, so when the helicopter became uncontrollable, he “dumped” the collective and rolled back the throttle. During the oscillations, the main rotor blades stuck the wire strike protection system, which resulted in substantial damage to the rotor blades. The pilot reported that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation.