All I want is claws for the beast races and webbed hands/feet for the Argonians, since The Infernal City makes several references to each.
This.
I'd rather they not cripple the ability of the beast races to wear certain helmets, gauntlets and boots, but their hands/feet should still be inhuman enough that they don't seem so perfectly anthropomorphic. I honestly thought they looked a bit silly in Morrowind, so this is a good compromise.