ThinkPad keyboards, with built-in mouse on home row. I like the layout, spacing, and short throw of the keys so much that I have a USB version for my desk, attached to a docking station.
http://shop.lenovo.com/SEUILibrary/controller/e/web/LenovoPo...
(I wish they still had the classic version, but the current version still beats any other keyboard out there, for my taste.)