Perhaps my expectations were too high for the game, given the level of hype over it and people throwing around 10/10 reviews. I am an experienced RPG player and am a big fan of many of Bioware's other games (BG2, Planescape Torment, Mass Effect). However, for me the game doesn't live up to the hype.
One of the biggest issues for me is the lack of player freedom early on and the length of time it takes for the game to open up. Player freedom is highly desirable for me in an RPG and I know this isn't 'open world', but the first two planets you visit felt very linear and railroaded. It takes ~15-20 hours of play before the game starts to open up and allow you to visit other planets, which for me is far too long. Compare with BG2, which opens up beautifully once you get through Irenicus' dungeon (~2-3 hours).
I also didn't find the plot very inspiring. Darth Malak seems like a very cliched Vader-clone type of bad guy (as many Star Wars antagonists seem to be). The main plot seems to be a fairly thin version of "you have to collect X widgets from this list of locations". Most of the dialogue is good, although there are some quite cheesy lines in there, as others have noted.
Otherwise, I think the graphics hold up pretty well given the game's age. The sound/music are very strong as well, although that is mostly due to them being heavily derivative from the Star Wars movies. The game doesn't seem to make many original musical contributions or have its own theme to distinguish it from other SW offerings.
The combat gameplay and character development systems are probably the game's strongest points, given that they are based on the 3rd edition D&D system, which is very well developed and highly regarded.
In summary, it's a decent game but doesn't live up to the hype. People who are both SW and RPG fans will enjoy it. However, imo, it isn't Bioware's best, let alone a candidate for best RPG of all time.