There could be a spoiler to BSG and possibly LOST at the bottom, though I won't talk about the details on what happened at the end I will discuss the manner in which they both ended. Read at your own risk I guess.
I'm not sure if I'm the type to go against the grain just to be different, but I know for a fact that my opinions and feelings change on a daily basis, especially when I'm presented with new information. I loved Mass Effect 1. It's one of my favorite RPGs of all time, and the only Bioware RPG I would call a masterpiece. With all shortcomings aside (inventory system) I loved everything the game was advertised to be. I don't care about shooting or any of that, although I'm an avid ArmA 2 player and I love simulation and games revolving around gameplay, rather than cinematic flair. But Mass Effect 1 was truly something I put a lot of heart into and for a game, that's saying a lot.
Mass Effect 2 to me downright sucked. I loved the characters, as usual, and loved the cinema, but everything else just didn't feel good to me. The dialogue and choice was lacking and although it still felt space opera, it just wasn't the same as ME1. And I don't mean that in a good way. I won't go into why I didn't like it as much as ME1, because it's just a feeling I have and I have zero desire to try and sway you to my opinion and get you to hate it too.
But Mass Effect 3 was the worst one of all. Terribly cheesy and corny cinematics, with terribly convenient character encounters, clunky combat on the harder difficulties, barely any emotion impact save for a few instances, and cyborg fucking ninjas. I could've swore I was playing Ninja Raiden Solid or some Japanese shit, and I was the most negative of all my friends about the entirety of the game. My favorite parts were the dream sequences and the characters. Characters being something so very consistence and incredible in nearly every Bioware entry and I can always count on that when buying a Bioware game. But seriously this game was just awful for the most part, and I was expecting the worst for an ending. I've had the game since launch and have taken my time since, going slowly, wanting to savor what fun I could extract from this terrible entry into the trilogy. There were some laughs (some not intended), some tears (again, some not intended), and some great shooting fun to be had (maybe a little not intended here...), and when I finally got to the big choice at the end I was in awe. Most of the battle cinematics so far were just so underwhelming but that final citadel battle- Oh man... And the final Earth battle- Oh man... And the choice? Well, I'm not sure what I think about that. I chose the middle one if that helps understand my point of view some more.
Now ignore what happened after the credits, please. That was pointless and was purely something to justify the ability to continue to play after it ended. I understand that since everyone shit their pants when Fallout 3 ended and they couldn't play anymore. But the actual ending...? It was great. They didn't give us shitty epilogues where all the characters had a big reunion and told their story and hugged and kissed. They didn't show life after everything ended. They didn't give us 100% closure, which is what you're supposed to do at the ending of anything. You can't just go and give someone a play by play on everything that happened. I just don't know what else people would've wanted from this ending. I just don't. Shepard died, the mass relays were destroyed to prevent races from traveling the stars before they were ready, and all major life ended up on a planet where they could begin anew, and forge a race combined from synthetics, humans, Asari, and whatever.
I took from it closure. My story was that of Shepard's, not anything else. This isn't Dragon Age in that it's about the world or universe, it's about you, the character. While most of ME2 and ME3 took that away with rushed dialogue, and in most cases, severely limited and autopiloted dialogue, ME3 gave back in an ending to your own story, and gave you a taste of what would happen to the world around you after you'd gone. That's more than you'll ever know when you die, depending on your spiritual beliefs of course.
So I'm a very negative, cynical person. I hate a lot of games and I'm never satisfied. ME3 gets a 6/10 in my book, where ME2 got a 7, and ME1 got a fat 10. But was this ending worth getting up in arms about? No. BSG and LOST had far worse endings, and there is such thing as too much closure and too many answers. In life, we never get all the answers or all the closure we need. When we die, loose ends are left behind, questions go unanswered, and our purposes are rarely, if ever, revealed. This ending was very telling of that reality, and I, personally, enjoyed it.
This post isn't here to convince you that you're wrong, because everything is personal taste. Was just hoping some people might consider it some more. Also, I've never read any theories or anything. I just played the game and muted my headset anytime someone on TS was fixing to spoil some shit for me.
Thanks for reading my wall of text, hope it wasn't a chore.