Chalk another one up for the ol' Model M, but I reckon it needs some improvements in this modern era.

I would pay $100 for a Model M clone with:

-USB 2 connection, plus inbuilt hub

-Windows keys

-Volume knob/keys

-Media control keys

Nice to have:

-N-key rollover

-LEDs under the caps lock key instead of way off to the side

-Apple keycaps

-Extra F-Keys

-Hardware switch to disable Win Key

-Extra shortcut keys that can be programmed in OS X