My Win 7 quad core for editing photos and videos, also built to play Crysis that I have hooked up to my big screen TV. I named it "Alice" for a reason.
I have to keep mine fairly simple and clean, because I project my laptop in front of my class everyday. But I still manage to slip in nerdery.
I've had this as my background ever since I took a photoshop class back in my sophomore year of high school.
Took me just under an hour to make this using Microsoft Word before taking a screen shot and cropping it in the images app on my laptop.
It's the G1 Marvel Megs from this site in my work, and here in home one of my creations (I do some bizarre erotic things on photoshop sometimes), but it's too "violent" to post it here.