Chatpad would be one. I like it not only for the function it just gives the controller a bit more weight and a different feel.
AX360 and AXPro headsets.
New Silver controller with transforming D-pad and textured controller surface.
My hacked together headset for use under my AX360s made from a horrible Plantronics low profile headset. Replaced the 2 inch mic boom a nice long flexible microphone that came with my AX360s. Easily the best one at picking up when I talk.
Cheap 4GB thumb drive to keep copies of game saves on.