The stories of Asimov were ground breaking, in terms of robots (he invented the term robotics), and his three laws of robotics - the guiding principles of many fictional robots today.
Pre-Asimov, many robot stories were scary products of evil minds, intent on causing harm or replacing jobs. Asimov was ground breaking, portraying the human side of robots, especially in his popular "I, Robot" series.
While this treatment of robots is now commonplace in popular fiction (Data in Star Trek, etc), humanity was Asimovs great accomplishment.
Bicentennial is a great potrayal of a human robot, and who better than the wonderfully talented actor Robin Williams, who can act in many outlandish and difficult parts with dignity (and humour). Williams' performance in this film is moving, graceful, and in some places humorous - Williams' quirky nature shines in the role of the confused robot Andrew Martin.
By placing Williams in a robot suit rather than use computer imagery, the character is real and believable, and the human characteristics of Andrew Martin are definitely there.
Sam Neil as "Sir" is the "father" figure of Andrew, and acts in his usual stylish manner.
Embeth Davidtz is lovely as Portia, the great granddaughter of "Sir", and a caring person - undoubtably confused about the intrusion of a robot into her life.
The special effects in this film are great, but don't go looking for them. This is not a film about special effects, they are incidental to the plot, merely supporting the premise of a futuristic robot, and the passage of time. The future city of San Fransisco is not as remarkably different from todays, and by keeping the environment familiar to viewers, the director has allowed the viewer to accept the premise, rather than be caught up in it (cf: Jurassic Park).