I bought a sealed dualshock 3 and it's genuine (tested with MGS HD collection) so I figured maybe it can help you as a reference when looking for original ones online :
Acheter Manette PS3 Sans Fil Sixaxis Dual Shock III Or (neuf) - PS3? 100% Garantie | Gamewalhalla
Sony PS3 Dualshock 3 Wireless Controller - Sky Games