I'm only going to review the ending of this game. The game itself has already been reviewed many times and I don't think I need to spend much time on it. Many people are claiming the ending to be horrible, I'm going to explain why it's NOT.
I've thought about this a lot. It's been nearly a year now. I think we must remember that in Mass Effect 3, the Reapers are already here. It's not like the first or second one, where we are doing things to prevent their coming and/or prepare ourselves for it. No, it's already happening, right from the start of the game. Throughout this game, literally, millions and millions of lives are lost within the galaxy. The reapers first landed on Earth, I KNEW right away that this was not going to end very nicely. Honestly, I think it's a little naive to think that this was going to have a sort of soft, happy ending. Forget about spoiler alerts, because "the Ending" is in the title. So if you haven't played it yet, stop reading now.

Based on the circumstances, Shepherd couldn't possibly survived. And really, I looked at his death as being highly honorable. Let's remember, that humans are looked down upon by the other races of the galaxy, and for a human to be the one to actually end the reaper threat was incredible. We also need to remember that many races, like the Protheans and thousands more before them, couldn't unite the whole galaxy for an epic final showdown the way Shepherd did.
And why complain about the ending? There's two main endings and a 3rd hidden ending. For personal reasons, I did like the ending. Honestly. Didn't like it. But I respected it. I thought it was fair, creative, unpredictable (huge plus), and logic. Sacrifices must be made in war, and the ending honors that concept, rather than be typical and having our main character(s) all survive and live happily ever after. I wouldn't have ending this game any other way and I truly believe that the ending is what the game deserves.