Superb writing and the best voice acting in video game history bring a wonderful world to iife.
Mass effect is truly a work of art as a video game. It pulls you in from the start and you never want to let go. We all know that Bioware is good at writing, but this time they have outdone themselves. The attention to detail and the depth to which they have gone to endow even the most trivial NPC with a rich background is unbelievable.
Sure, the combat has a lot of problems but the game is all about the story, which is superb. Not only is the overall plot with the difference races quite interesting and very well executed, but the side quests amazingly entertaining as well. The influence you can have over your actual character is quite impressive as well.
All in all, Mass Effect has got to be one of the best games I have every played in my life (and I am also playing Assassin's Creed :).