My keyboard of choice is the IBM M Keyboard. It is just about indestructible. The keys click which I really like being a touch typist. You know when you make a mistake by the sound. I also tend to be a little hard on the keyboard and it continues to survive. The keyboard has a great feel. The keyboard was made in 1989 and I have had one ever since. I have tried many other keyboards, but I always go back to my IBM. I have 3 of them in reserve in case anything happens to mine. I recommend the keyboard highly if you can find one.
You can buy a redesigned model at this location that I found:
In 1996, a company called Unicomp bought the Model M design from Lexmark which produced the keyboards for IBM. Unicomp sells replacement parts for older IBM/Lexmark keyboards, and will repair just about any keyboard manufactured by themselves. Their new keyboards are slightly different than the original. The originals can go for $150 or more and the new redesigned models go for about $70.00.
The keys are replaceable if you do wear them out.