Eh... not exactly a robot butler... more like android mousey secretary.
My android butler should be able to wash my dishes, wash my clothes, vacuum (when I'm not at home... that way I don't have to listen to it), remeber to Tivo the shows I forget, draw my bath, and have an arrogantly bored British accent that says "Yes, sir," but with "I-hate-you-but-you're-richer-than-I-am" tone to it.
And perhaps shaped liked a Dalek... with the ability to transform... or something...