I would have to say my good ol' Razer Naga is the one peripheral I couldn't live without.
I couldn't live without the WoW Cata mouse. Now I am undead. (Or not.)
My R.A.T-7 mouse and my G19...I love them.
steelseries headset. but i also appreciate the i7 and reliable router.
Love my logitech G9 mouse and G13. Makes WoW FUN!
My Logitech Mx500! It's an antique!
Keyboard and mouse of course though someday i would love to see the ability to use a controller. D3 on console worked so well that I think the controller could be implemented in all non-rts blizzard games.
my Kingston HyperX SSD.. It has changed the way I game forever.
My keyboard is from a 286 system, sturdy as hell. The day it dies will be a sad day indeed. Also like my Logitech G9 Laser mouse. I use an old, rigid hard surface mouse pad that's easy to clean. And my 24' widescreen rotating Samsung monitor that I really love.
The gaming peripheral I couldn't live without is my set of speakers. Sound is immersion to me. I need to hear it, I need to feel it.
Most important: my awesome Razer Imperator! cant play without it :)
I wont be able to play Wow Without my LG 24" Full Hd monitor(24MP55HQ).
I use a Razer Nostromo keypad and a Steelseries wow mouse. In my opinion the ideal combo for playing MMO's
Don't have a naga anymore, but my nice little usb mouse is awesome... WoW on a laptop with the finger pad is just painful >.<
My Naga mouse, I honestly don't know how I managed to play before I got one. Going back to a regular mouse now just seems insane.
The cosplay contest is always my favorite! and eSports!
Razer Naga Mouse *-*
My trusty old logitech keyboard. I've had this thing for like 8 years now.
Couldn't play without my headset!