I recently ordered (and spent two hours tracking down) two Das Keyboards. It's a German-engineered keyboard with loud clicky keys that offer great tactile response. The keys are individually weighted based on the approximate pressure applied by each finger (i.e. weaker fingers require less force), thus making it feel more natural.
None of the keys are labeled - Pure black paint. If you buy one of these, you probably already know how to type.
Already I feel like I'm typing faster. More importantly, however, I don't find myself second guessing whether a given keystroke went through. I feel it, I hear it, I know I didn't miss the key. That's a good feeling when you spend 8-16 hours a day at a keyboard.
But even more impressive than that is a feature I haven't seen in years, and never knew it had a name: N-Key Rollover ensures that no matter how many keys I press at a time, they'll all make it to the computer. Most keyboards only support 3-Key Rollover, which actually only supports two simultaneous keystrokes despite the name. If you press a third key, the keyboard scan codes get all wonky and the keyboard sends an erroneous code to the computer, thus you never know what you're gonna get. But with N-Key Rollover, each key is controlled independently.
Sweet. For someone like me who plays computer games pretty often, that's a big deal. I find myself very often holding down shift + W (i.e. "run forward") and want to hit "A" at the same time to shift to the left (per standard WASD layout); but the game didn't see the input and my character would get shot. So now I can strafe left in a full sprint.
So why did I buy two?
The keyboard I was assigned at work is one of the crappy membrane type, which I hate but can live with. But more importantly, the keys are in the wrong place! The keys are designed at a diagonal inward slant - the top of the keys point toward the middle of the keyset. On top of that, the backslash/pipe (\) key was moved to the right of the slash key (/). As a Developer and overall geek, I hit the backslash key very often and don't always remember the wonky keyboard has the keys in the wrong place. Can you imagine entering a DOS command and random backslashes become enters?
C:\> del c:\temp
C:\> projects\myProject.*.dll
Crap!
OK, so it stops and asks with a y/n prompt. So let's say you want to delete a file called Y. My point stands.
And you don't even neccesarily notice it because the top of the Enter key was extended to cover the hole left by the woefully missing backslash, thus it feels like you hit the backslash properly. So you don't double-check your command, because dammit I know what I typed.
Call it Ergonomic. Call it New-Wave. Call it Designer. I don't care, I call it Broken. Messing with the layout of the keys is the single worst mistake you can make as a keyboard manufacturer. Thankfully, that problem is now a thing of the past. Pics are in the Gallery under "Subsequent".