Here are a few NeoGeo hardware-themed pics:
And a few Nakoruru ones for a theme I was working on:
This is wonderful little image looks amazing on the E1000 screen. It was drawn by Ken Sui-Chong, and features Capcom's Morrigan, from Darkstalkers:
And finally, a colourful burst of bullets from a badguy in the Dreamcast game, Psyvariar 2, some animated Gunbird boobs, Magical Drop's World, Pylon Man from Ai Cho Aniki, a chick from ... That Psikyo game, wossit.
Magical Drop's World:
There are a bunch of other non-game and not-work-safe ones right here. I've removed 'em from this post to save tender souls from delicious japanese boobage. =)