Okay, this has been done before, but previous threads often refer to keyboards that are no longer available.
I'd like people to list rubber dome keyboards that are good - for rubber domes - and available off-the-shelf. Same for scissor-switch.
I'll start: the Kensington Keyboard for Life
For only ~$20, this is a pretty complete office keyboard.

They are alleged to be long-lasting, and come with a serious warrantee. Key press is polite - nothing exciting, it kinda reminded me of the matter-of-fact feel of retooled MX Browns.
Even has a metal backplate.
Downside is that the rest of the case is plastic, and feels pretty budget. For the price, this is something you could distribute to office employees without worrying too much about durability.
But what do people find pleasant to type on in the off-shelf rubber dome world? Scissor-switches are acceptable too. For example, which is the best of the current Logitech PerfectStroke keyboards? I heard they started cheaping out with the K740.