For sheer comfortable typing, there has still been no keyboard built that approaches the great original IBM PC/XT keyboards. The positive key feel and sculptured key layout, make this keyboard a joy to use for hours at a time.
When all of our PC/XT machines became obsolete years ago, I collected several of their keyboards, which I still use on each new computer, now connected via an inexpensive USB-to-PS2 dongle. I have one going strong on a Vista machine.
The buckling-spring technology that makes those keyboards so great, passed to Lexmark when IBM spun it off, and now Lexmark has sold the rights to the technology to Unicomp Inc. You can order the original IBM-style keyboard, or their own newer designs using the superlative buckling-spring technology, at http://www.pckeyboard.com/