Since I'm smart but physically weak (i.e. a nerd), robotic limbs are probably useless on me. If any part of my body could be robotic, then I'd choose a cybernetically enhanced brain. For one thing, it would give me super intelligence; for another thing, if my body fails then my consciousness could be uploaded into a computer so I wouldn't have to die. Since souls don't exist, making my brain robotic doesn't make me any less human if my personality is intact.