Despite my love for modding, I've shied away from doing much to by Xbox 360. My main reasoning is likely obvious; I fear the RRoD and do not wish to run the risk of voiding my warranty. However, if you're not as worrisome as I, you could add a neon glow to your console.
Extreme Mods has created a new exterior case for the Xbox 360 that is cool enough in the light, but gets better in the dark. The XCM Pearl Glow is translucent, allowing you a view of the inside of the console. Turn off the lights and the whole thing glows neon green for all to see.
Sure, the green glow might seem a little cheesy to some, but if that's your thing, you should be able to pick one up from Extreme Mods soon for an undisclosed price.