Achilles

You might not have as much of an issue with BioWare's writing in Mass Effect, actually. Part of it's due to the less stupid-sounding dialogue (the fact BioWare chose to write your PC's lines as if s/he were older than 12 helps), but so does how they deliberately tried to be morally ambiguous. I can't say BioWare succeeded in that regard, as I never ended up having to make any tough moral choices, but the main villain had (marginally) more depth than Malak and had actual justification for his actions. It was also a nice change of pace that 'evil' characters were more ends-justify-the-means types who wanted to save the galaxy as badly as good characters did.

ME also explores some more mature themes than KotOR did. Racism (well, speciesism) comes up very frequently during the game and gives it a much more serious feel. Nationalism also does to a lesser extent, but it's kind of blurred with the former.

Not to say the game is consistently well-written, though. There were a number of lines which caused me to roll my eyes, and the justification evil PCs have for their actions isn't always very... well, justified. It is most of the time, but there's still several instances where it seems forced. Though thankfully none of those instances are relevant to the plot.

But anyways, if you'd wanted a review for the game I'm sure you'd have looked for one. It's no MotB, but I'd still recommend it to anyone who likes story-driven RPGs.