One of the best RPGs of this generation
Mass Effect's storyline is actually very well thought out. A driving storyline and plot makes for a very user-involved experience, and each choice in the game affects how the game plays. Different choices lead to different responses from different characters, and there's a multitude of choices to be made throughout the game, making it very replayable. I can't really say much more about the game's story, because it's so rich and full. Suffice to say, it's a great variation on the ages-old tales of one man against impossible odds.
The voice acting is top notch. Veteran actors, ones like Keith David and Lance Henrikson and Fred Tatasciore, provide voices for many of the key roles in the game. The roles are played with passion, and all the voices just seem to meld perfectly with the characters. Music is well done, if a bit repetitive. The galaxy map music is very atmospheric, and really lends the size of the game credence. No complaints here for sure.
Graphics are, in a word, breathtaking. I have some issues with them though. They overextend the 360's hardware. For those of you who played Halo 2: remember the textures "popping" in and out in the game? It's the same here, but much more pronounced and the framerate will occasionally lag. Most of the time, it's after a level loads, but the textures load slower than a level, so you may have to deal with Quake textures for a bit while the texture image catches up with the game.
The "conversation wheel" allows you to be Sir Chivalrous the Good Hearted or Lord Asshole the Bastard. The conversations are important to the storyline, so pay attention. Another really nifty feature is the availability to replay the game from the start with your character from the previous game. I started a new game today after beating it yesterday, and it allows you to replay the game and go in a different direction (for example, I'm being a complete dick through this playthrough, while last play I was a good guy through and through) and the higher base level means things are easier. You also start with the gear you had at the ending of the last game. There are a few gripes though, such as driving and friendly AI. The driving is a bit wonky, and feels loose. The gun on the top doesn't do near enough damage to be a 155mm cannon, the shields recharge too slowly, and the armor must just be for show, because it wouldn't protect against a well-placed rock.
Overall a must buy.