I've used a couple dozen keyboards over the years.

Currently I use a Microsoft Comfort Curve 2000 keyboard at home and at work.   It's not too huge and it's not too thick and it's not too curved.

My work keyboard is fairly unique.  When I was poking around in our admin's equipment storage room looking for something else, I happened upon a completely blank version of the Comfort Curve 2000.   I grabbed it in an instant. 

It's like the Das Keyboard - no lettering.  Who needs 'em?  I know where the keys are...