A great game held back somewhat by bad design decisions.
BioWare took the Star Wars license and did what many companies failed to do, make a good Star Wars game. It features many different good things about it, and one of them was the story.
The story of KOTOR starts off pretty simple, and stays that way until after you become a Jedi and the story starts to unravel. A couple of big, exciting plot twists keep you glued to your seat as you play through this game. Although these twists help make the story better, much of the game isn't as exciting as one would hope it to be. Along with the story comes the atmosphere and general feel of the game. BioWare manged to capture the Star Wars universe, and it's incredible fun just exploring and trying to see thing from the movies. The writing of the side quests and NPCs is great, and your companions are very memorable and have interesting things to say along your journey.
The graphics were great when the game was released, and it doesn't look half bad today. It depicts the world well enough and helps to deliver the story. The music is good, although not too memorable, and the voice acting is top notch.
The combat is a little shaky. It doesn't seem to flow as well as it should have. It tries to do a real time strategic combat system with pauses implemented, but it doesn't feel as fluid as a top down game such as Baldur's Gate or Dragon Age Origins. BioWare should have opted for a more action oriented combat style in the 3rd person over the shoulder perspective.
In short, KOTOR is a really good game, but it doesn't do much great to earn a 9. The story was average with some bright spots, the game play was decent, and everything else was very good. There isn't much to complain about, but there isn't enough to praise either.