I've finished Mass Effect. Can't say I'm satisfied, but the fact that I completed the game is more than testament to how good it is. It's riddled with bugs, especially those involving collision detection (I think a nice physics engine, perhaps Havok, could help with that) – hopefully that's fixed by Mass Effect 2. I can't say I'm a fan yet, since I have no intention of collecting the trilogy or preordering the remaining planned two games.

(By the way, why do so many of the biotic spells feel like Force powers? Hm….)