This came out in 1999, but I didn't see it until 2015. It's based on Isaac Asimov's 1976 novelette of the same name, as well as Asimov and Robert Silverberg's 1992 novel "The Positronic Man" (which itself was based on the novelette). I must have read the original story at some point, probably in the early 90s, but I don't remember it at all. And I've never read the novel. In any event, I think the movie is probably fairly different from either previous version of the story, but I couldn't tell you how. (Someday I'll probably at least reread the novelette, at which point I'm sure I'll mentally compare it to the movie.) Anyway, I guess the movie didn't do very well critically, but I've always wanted to see it. And I ended up liking it more than I expected to. The main character is played by Robin Williams, and "Bicentennial Man" definitely feels a lot like a Robin Williams movie... but I also think, however much the story may have changed, it feels at least somewhat like an Isaac Asimov story. It's kind of odd to mix those two dynamics, but in my personal opinion, it kind of works. (Two great tastes that unexpectedly taste pretty good together, if not really great.)
So, the movie starts in 2005 (which means it was slightly futuristic when it came out, but by the time I saw it, it was set in the past, and we still didn't have household robots). There's this guy named Richard Martin (Sam Neill), who buys a robot for his family, including his wife, Rachel, his 9-year-old daughter, Grace, and 7-year-old daughter, Amanda (Hallie Kate Eisenberg). The robot is played by Robin Williams, though I couldn't tell you if he was actually wearing the robot suit or just providing the voice. Anyway, the family decides to call the robot "Andrew," and he calls them Sir, Ma'am, Miss, and Little Miss. While the older daughter doesn't like him (she's a typical rebellious tween), Little Miss soon comes to like Andrew. Meanwhile, Richard begins teaching him about humans, and encourages him to pursue an artistic career (among other pursuits). He even opens a bank account for Andrew, who is allowed to earn his own income.
Years pass, and the girls grow up. Little Miss has romantic feelings for Andrew, though he seems oblivious to this. So she marries someone else, and has a couple of kids of her own. And... various things happen throughout the movie, which is divided into different time periods, though I don't always remember what happened when. At some point, Andrew gets his face upgraded to display emotions, though personally I couldn't tell the difference. Also, he builds himself a house on the beach, after Richard agrees to let him have his freedom. (Andrew still wanted to live with and serve the Martins, but for some reason, Richard didn't want him to stay. I have no idea why.) Sometime later, Andrew goes on a journey to find other robots of his type, hoping some of them might have developed human emotions and independent thinking, as he had. But apparently he's the only one who did. Finally, he meets a feminine robot named Galatea, who at first seems to have a human personality, but he soon learns that that's just because of an artificial personality program her owner had installed, not a true personality like Andrew's. However, her owner, Rupert Burns (Oliver Platt), is a roboticist, himself, and creates artificial flesh, which allows Andrew to appear fully human. (From this point on, he's definitely played by Williams in body as well as voice.)
Andrew goes back to see Little Miss, and is surprised to find that she's now an old woman. He also meets her granddaughter, Portia, whom he initially mistakes for Little Miss. (She's played by Embeth Davidtz, who also played Little Miss as a young adult, though personally I didn't even recognize her as such, because her hair was a different color and style than Little Miss's had been... and I suck at recognizing faces.) Anyway, Andrew and Portia don't get along at first, but over time they become friends. And when her grandmother dies, Andrew and Rupert begin working together on creating new organs, which Andrew designed both to make himself more human inside as well as out, and to help humans live longer. And... eventually, Andrew and Portia fall in love. After that, Andrew wants the World Congress to declare him officially human, so that his relationship with Portia can be legally recognized. That doesn't happen the first time he petitions Congress, but many years later, when he's 200 years old (hence the story's title), a new generation of Congresspeople do finally recognize his humanity.
I'm sure I'm forgetting lots of important things from throughout the movie, as well as leaving out an important detail about the end. (Though as usual, I feel like I've said way too much.) But the movie has a lot of funny bits (and some ridiculous bits), as well as some reasonably good drama and philosophical questions about what it actually means to be "human," I guess. And there were small appearances by a few familiar actors, including Stephen Root (as the head of the company that made Andrew), Bradley Whitford (as Little Miss's son, Lloyd), and Lynne Thigpen (as the head of the latter World Congress). And... I don't really know what else to say, except that I'm really glad I finally saw it.