Guys, thanks for the robust comments on the previous Mass Effect post. I have to confess that I'm not yet done with ME2, but I'll offer up what insight I can given my progress up until this point.
[POSSIBLE SPOILERS AHEAD.]
I've focused a bit on how the first Mass Effect game plays on racial tensions but it also harbors some idealistic memes about race, culture and identity, too. In the comments, some people mentioned their feelings towards the blue-skinned Asari.
All the Asari you meet in the game are female; they're a fearsome race with psychic powers, martial prowess and business holdings all over the universe. When Liara, the Asari who joins Shepard's mission in ME1 talks about her race's mating habits, I honestly felt like I was hearing an epihphany. She talked about how it's preferable that the Asari mate with with non-Asari species because it'd stop their society from reaching an evolutionary dead end Another party member named Tali also said similar things how her race, the nomadic Quarians, treated their coming-of-age pilgrimages. It's important for journeying Quuarians to bring back a new discovery that would help sustain their knowledge and technology so their centuries-old fleet could continue their exile. You can see that Bioware's given thought not just to the plot of the games, but to the societies in these worlds and even individuals, too. It's rare that any two asari, for example, will look alike. They're all blue, yes, but the skin tones and marking differ with great variety. While the conversations with Liara a clear set-up for a romantic interaction between her and Shepard, it felt like an incredibly progressive organizing principle for a whole society.