Warning: Spoilers
There can be many ways to rate this video game: playability, storyline, graphics, voice acting, etc. The best way to rate it is by what it delivers and its final intent. First of all, you must understand that the central story and the teachings of Kreia (and the voice actor herself) are the greatest reasons to play and own. The expansion of the Sith teachings is marvelous, especially if you choose to go 'dark'.
The great things about this game: 1. Kreia. I hated this b**** when I first played, because she was always bitching about something. Yet when I began to interact with her more, the more I began to understand the grand design of her teachings and master plan. This means that if you go through it quickly just to fight things (as in a platform VG), you are going to lose much.
2. The atmosphere. The one thing I disliked in Lucas' movies was his homage to the juvenile and pointless serials of the 1940s. The Sith Lords allowed the Force to be something of a 2-sided blade (pardon the pun), both the Light and the Dark are perilous.
3. Bao-Dur. I really liked him; so sorry that others feel his character was lackluster. I knew guys in the military who were just like him.
4. The Exile. I like the idea he/she can be so cynical and detached from good or evil. A true outcast - you can mold him/her like you want to.
5. Good re-playability. Things change from different character types and genders. I've played this game probably 10 times, playing both male and female, good, neutral or dark. There is always something new to see even if you beat it.
6. Good Story. I love the Machiavellian ideals of Kreia. She is truly the most fearsome Sith Lord I've seen.
7. Dxun. Fun area; I like going one on one with the armored lizard without anyone else in the party to back me up.
8. Mira. I'm a guy and I have a love for redheads.
The things that were not so great: 1. Quirky and lost endings for characters. Thanks LucasArts and Obsidian for shearing off more of what could have been the best VG I've ever played because of your Sith-like greed.
2. Useless characters. G0T0 for example. I never used him nor did I like him or his yacht.
3. Gliches. These can be less numerous on the XBOX version. Again, the powers-that-be decided to rush things (but we already know that).
4. *spoiler* Fighting Darth Sion over and over again (like you did in KOTOR I with Bastila and Malak). I like Sion; he just wasn't used good enough - and with him, you really didn't need to confront Darth Nihilus.
5. Darth Nihilus. Too vague, too aloof. An extra villain that could have been merged with Darth Sion. The only thing I think the designers banked on was his strange white mask.
The neutral things would be about everything else.