Current setup is a turtlebeach x12 and a coolermaster devastator mouse and keyboard. It's pretty crap, but such is the life of a broke college student.
It's like a really portable monitor with virtually no screen size restrictions, it's all of my nerdiest dreams in a little rectangular box. Well, not all of them, but you get the point.
For me it has to be the Kuhler 1250, I've been wanting liquid cooling for my rig for a while but I just haven't gotten around to buying it and this would be a great addition to my PC.
My favorite thing would probably have to be the sound output, it just looks like it's 1000 times better than the typical laptop, and then there's the battery life which is enough to last me most of a boring car trip.
The repositioning of the side buttons onto the back of the phone and the dual screening option. Very useful for when I don't want to exit the app I'm using.