My favorite keyboards to type on are the three that I am currently using on my computer that I am sitting at right now - Why so many, because I love all of the options:
Microsoft Wireless Keyboard 6000 v.3 (This is the quiet soft touch one)

USB Microsoft Natural Keyboard Elite (This is the comfortable one)

An Original IBM PS2 Keyboard KB-8923 (Yes, that's right the original bullet proof super tactile spring loaded keys, so you can type only one letter instead of three letters by accident.)

I have several other keyboards from AOpen, Gateway, IBM, the $10.00 no named brands, Logitech wireless and USB and I even have one of those fabric / silicone roll up / flexible keyboards that I keep in my tech bag as a backup keyboard. But the ones described above are all attached to one computer. I also have 6 mice both wired and wireless attached to this computer also. :)

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Permalink Reply by beavis5551 on September 24, 2009 at 1:53am

those old IBM keyboards where rock solid.
I had an IBM server console keyboard which had some kind of metallic backplate.... i am not sure what material and why they had these... unfortunately, the connector died...

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Permalink Reply by Greg De Santis on September 24, 2009 at 2:08am

Yeah all of my original IBM keyboards are all still fully functioning, including the one that came with my original IBM PS2 Model 25 8086 back in the early 1980's. These spring loaded monsters are sure built to stand the test of time. I am still amazed after all this time how easy and comfortable it is to type with it.

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Permalink Reply by Zune80 on September 24, 2009 at 1:42am

I have the same keyboard as Greg. My primary is the Microsoft Wireless Keyboard 6000 v.3 pictured below (I don't like the mouse that came with it and won't use it), and I also used the second natural keyboard for yearssss when it came out, but I updated that one to the Microsoft Natural Ergonomic 4000 keyboard (Black and Silver) about 4 years ago I'd say. I use both keyboards for different things. I love Microsoft's keyboards and mice and will always use them.

For the record, I use the Microsoft Natural Wireless Laser 6000 mouse. :)

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Permalink Reply by Greg De Santis on September 24, 2009 at 2:21am

The funny thing is that Microsoft is one of the only companies that is incompatible with its own products.

The first generation of the Microsoft Natural Keyboard Elite PS/2 connection will not work with Windows XP SP2 and above, because Microsoft fundamentally changed the PS/2 hardware driver making it most compatible with the last revision of highest end PS/2 motherboard hardware chip, and least compatible with the original legacy PS/2 chip. Now the actual PS/2 hardware driver is incompatible with Microsoft's legacy keyboards, so when you plug in a first generation Microsoft Natural Keyboard Elite PS/2's your computer will lock up on boot - the solution is to use the USB version. Microsoft knows but will not downgrade their driver since PS/2 is in obsolescent.

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Permalink Reply by Zune80 on September 24, 2009 at 2:50am

I had some issue a few years ago with the PS/2 connector on the keyboard interfering with my Cubase SX3 software for my recording studio. It was odd, but the solution was to use a PS/2 to USB adapter and it worked like a charm. :)