An amazing experience you will never forget
This game is definitely one of the best games I have ever played, and if that makes me sound like a fan boy... you are absolutely right.
In short, the story is fantastic from what you could have expected from a sci-fi game, nothing ground-breaking, but has all the things you'd come to want from one.
While light on RPG influences in comparison with other games in the genre, ME2 instead focuses more on telling a story and action. You won't spend several hours walking around a world looting items and getting skill points, rather each level is filled to the brim with great dialogue, immersive atmosphere and action filled gunfights.
Each mission level is unique and you never feel the game gets repetitive, graphics and sound is excellent.
The characters are where ME2 really shines though, your squad members are some of the most well written and memorable characters I have ever encountered in a game, and the voice acting is top-notch all the way through.
It's not a perfect game though, as there can always be improvements. Scanning planets for minerals quickly gets boring, and too many planets serve little purpose than just that.
You might also feel a bit limited in your movement as most maps are rather linear, although you are mostly free to choose in which order to do the missions.
The cover system can also be a little messy sometimes, but works well enough for the most part.
However, aside from these (very minor) flaws, ME2 is an almost perfect game for me, and the DLC's just keep improving it with more missions, equipment and story lines.
So, whether you want to play a great RPG with a superb story and characters, or just want an action packed shooter, ME2 is definitely worth playing. Here's to ME3!