I actually enjoy buying accessories. Soooo:
PS3: Dual Shock 3, Component Cable (shared with Wii), PS2 Memory Card Reader, keyboard
Xbox 360: Charge and Play kit, 2nd Controller, Live Camera, Gamestop controller
Wii: horizontal stand (?), Wii-motes and nunchucks, Wii Zapper, classic controller, Datel Power saves kit, Nyko Charge station.
Pretty tame list considering how much I bought last gen.