Sleeved Cables, Lights, Paint, & Coolant Dye for your Gaming Computer 

The most commonly-applied aesthetic alterations to systems are often cable sleeves, lighting modules/effects, and front panels.

Sleeved cables and coolant dyes in action!

Pre-Sleeved Cables (~$10 ea.): Almost every high-end system at gaming events will feature individually-sleeved cables, often using high-end weave/mesh materials that give off a brilliant accent to the system's interior. If you don't have time to do custom sleeving, but you've got money, pre-sleeved cables are available from Corsair (more expensive), SilverStone, NZXT, and other companies on an individual basis. Make sure these are compatible with your PSU (for the most part, they are inter-compatible with all PSUs, but some high-end PSUs may have different headers). Sleeved cables can really clean up a system interior. It won't affect performance, of course, but makes for a professional look. If you'd rather save money on cables and do the sleeving yourself, continue on!

DIY Cable Sleeving Kits (varies, but cheaper!): Our professional case modding friends are largely responsible for advancing the industry of computer aesthetics, pulling us by the heels out of the era of beige cases. We briefly met Lutro0 of Lutro0 Customs at PAX Prime 2013, known best for innovating new techniques for DIY cable sleeving. Lutro0 has some highly-affordable custom sleeves available on his website, along with headers and all the other necessary supplies. You can put together a total PSU cabling kit for pretty cheap right now, with the current active sale. Check his FAQ for information on how to actually sleeve cables and what you might need (it's not that hard to get started, it just seems intimidating).

 Kingwin FPX-003 Front Panel Controller ($37): Front panels are an awesome way to soup-up a system's room presence while still offering some functionality to the user. This front-panel fan controller can regulate voltage on four channels, displays temperature read-outs (in C & F) on its LCD, and is fitted with SD & CF readers, along with an eSATA port. Alarms can also be set, so if your system starts exhibiting higher temperatures, the unit will warn you and take the programmed action.

PC Lighting Kits

 NZXT HUE Controllable RGB LED Strip ($33): We featured a mini version of NZXT's HUE RGB lighting system when reviewing the Phantom 820 case, but this is the real deal. The HUE is capable of a full RGB spectrum of colors with its included LED strip, so if you wanted deep purple, dark red, light red, blue, yellow, green, etc., then you can configure the HUE to output that color. This is done with a custom LED controller in the HUE, which is connected to a 3-dial front-panel (spin the dials to mix colors).

 NZXT Sleeved LED Strip ($14): If the HUE is a bit too much bulk and specificity for your build, NZXT also makes single-strip, 3-foot sleeved LED kits (with expansion slot panel for toggling the lights). These are excellent for achieving a spot-lighting effect when using windowed side panels, creating a sort of "car showroom" look on the core components. We'd recommend routing the cable around the side or top of the window, which will create a cascade / glow effect on certain types of acrylic or Plexiglas windows.

 BSMods 16ft RGB LED Kit ($35): We've worked with BS Mods a number of times while covering their case mods and, having seen these LED strips in a few builds now (like the Throne Industrial), we're pretty impressed with the resulting effects. These guys actually build a lot of the industry-famous case mods, so they've got the experience behind them to know what makes for a good lighting strip. It gives off 16 true colors, includes a remote (to program the colors), and can be cut every 3 LEDs, so if you wanted to split the strip into multiple segments for highlighting, that can be done.

 Logisys 5 Laser LED ($6): I've previously used this one in an Iron Man case mod to create a glowing visor effect. These highly-directional, vibrant laser LEDs are more intense than mood lighting LEDs, making for more of a 'rave effect' inside the case. I find this works best when you're trying to highlight an exterior component from inside the case (i.e. mounting the lasers inside, then pointing them out meshes / cut features / etc.). These are also sold in blue.

Case Paint, Coolant Coloring, & Sound Dampening 

Liquid Coolant Dye ($9): For anyone with open loop liquid cooling, one of the major advantages of such a setup is the ability to accent the interior with dyed liquid. Blue, red, and even white liquid coolant were all spotted in our "Best Case Mods of PAX 2013" round-up. Coolant dye can be picked-up for a couple of bucks and added to the loop, which will pump it through the system and dye the liquid.

UV Case Paint ($23): A vial of UV reactive case paint will help illuminate / spotlight specific components or regions within the case when under a UV light (like this UV cold cathode). If you've got a paint job in mind for your case -- maybe to accentuate MSI's dragon aesthetic on the borders surrounding the board, for instance -- this invisible paint will only light up when under a blacklight.

SilverStone Silent Foam Sound Dampening ($16): For louder systems, these sound dampening pads can be stuck to the sides of the case to help buffer the mounting cracks and dampen some of the fan noise emissions.   

Let's move on to functional upgrades, including GPU cooling, CPU coolers, video card options, and SSDs. We'll also make a couple of peripheral suggestions (mechanical keyboard, gaming mouse, and gaming headset gift ideas). Page 2 here.