Star Trek's Data is poor planning. Why make it want to be something it isn't? Don't we have enough body issues of our own without giving them tour computers?
I'm no expert on Star Trek so I may well get crucified for this, but I thought the story went that the first attempt - Lore - was fully aware that he was superior to humans in every way, and turned out to be a complete and utter bastard. So, they went back to the drawing board and made a new android - Data - that believed being human was awesome (and by extension that he was ultimately inferior).
In other words, you better make damn sure your hyper-intelligent robot has some sort of hardwired mental failsafe in place before you turn it on, or it'll take about 0.01 nanoseconds to figure out it doesn't need us and it sure as hell doesn't need to do what you tell it.