Mass Effect just so happens to be a most excellent game, in my opinion.
The gameplay is interesting, with a variety of difficulty modes for the completionists, and also benefits that carry over from one game to the next playthrough. Completing certain achievements may give weapons a passive ability boost, or unlock that weapon as a bonus skill for any character created after that point. However, some of the explorable planets seem like that they have been thrown in just to provide something to look at, And the A.I is somewhat lacking in the intelligence department.
Moving swiftly onto the graphics, on a standard TV set the game looks beautiful, with film grain effects and motion blur to activate in the options if you so desire. However, it shines upon a HDTV. The scenes in space look gorgeous, with many thousands of stars, planets and nebulae to distract you from what could be an important scene. On the flipside of that, though, some of the characters do not look as polished as others, but the magnificent alien races will soon make you forget that.
Mass Effect also has a fully original score, that accents the storyline perfectly, in my opinion. A sinister orchestral rise at a plot specific moment involving the antagonist, to the little elevator jingles in the Citadel ( accompanied by funny advertisements and also chatter from your team ) make the game a "bit" more awesome.
My verdict? A masterpiece of game design, storytelling and musical expertise, combined to make an absolutely epic game. Let's hope that Mass Effect 2 improves upon the few flaws in this game, and builds upon it's strengths.