Keyboards are often neglected among even the greatest PC builds. You're prepared to invest hundreds in your graphics card and processor, but the keyboard isn't always considered the same way. A new processor might make your rig run faster but a new keyboard can do a lot as well, and for the less technologically-savvy, plugging a USB into a computer seems like a much easier option.
The best keyboards tend to be mechanical. Mechanical keyboards differ from conventional keyboards due to their internals using specially-made keyswitches. The end result is a noticeable clacking noise, and clear feedback when you've pressed a key. Describing the experience doesn't do enough to do it justice. It's something that has to be tried out for oneself.
Tim Schiesser and I have both reviewed mechanical keyboards. Tim wrote a review of Corsair's K90 Vengeance, while I looked at the Das Keyboard Professional S. There's a new breed of Das in town, so if you've been holding off then now is the time to buy in. The new model packs media keys in, without sacrificing the sleek lines of the design. The new features are built into the 'F' keys, and come with their own LED lights. Thinking about how well designed the LEDs in the Das Keyboard line-up are, it sounds very appealing.
If you want the mechanical feeling but not the mechanical sound then the new model with media keys is available with both MX Cherry Blue and Brown switches. My Das Keyboard contains Blue switches, but there's nothing to stop you going for the Browns, which offer less noise and require less pressure to actuate.
Assuming you had the technical know-how you could possibly even cook up a script for an existing Das Keyboard, enabling the functionality for the media keys. If you don't, or if you haven't yet moved into the mechanical market, then the Das Keyboard should be on your list of contenders.
The new media keys add functionality which previously wasn't included on the device. If these keys were essential you had to look elsewhere. If the sound of your mechanical keyboard isn't music enough to your ears then the addition of these functions could only make your music experience smoother, to go with your typing.
The new breed of Das Keyboard retails for $129. The cost might sound unjustifiably high, but when you try one you may be convinced otherwise.
Fun Fact: the media keys were available on older Das Keyboards for a short period of time, according to some people. Due to issues with OS X compatibility these keys were dropped pretty swiftly, so this is technically a re-feature.
Source: Das Keyboard