[Error: unknown template qotd]Lt. Commander Data, no contest. But runners up include:

1. Robin Williams' portrayal of the android in "Bicentennial Man."

2. Gir from Invader Zim! He's so cute!

3. Data's brother, Lore; despite him being evil.

4. Johnny 5 from Short Circuit

5. Marvin the paranoid android

But I love most fictional robots, so choosing is very hard.