Yes, Grace Park is HOTTER than hell, however I don't look at her and immediately think, "robot," though she played one on TV.  By the way, you can catch her on the upcoming redo of Hawaii Five-O this fall.  She plays Kono who was played in the original series by a very large Hawaiian guy (Zulu).
Anyway, I have to go with my childhood and say the robot from Lost in Space.  And by the way, he did have a name.  It was B9 (as in "benign").
If you've got an extra $25,000 laying around, you can purchase a childhood memory:  
http://www.lostinspacerobot.com/index.html