Hmmm...perfect...perfect?
No, no I don't think so.
Make no mistake, Mass Effect 3 is good, it's great, hell it's one of the best games I've ever played IMO. But it is not perfect.
I don't just mean the ending. Throughout the game I encountered a few bugs (including one that erased all progress towards trophies I hadn't obtained yet. I had to start all over on killing 5000 enemies dammit!), serious frame-rate drops (particularly on the Citadel), and the occasional super speedy, or just plain missing dialogue. Subtitles would show up, but there was no voice to go with them.
I don't know if this only happened to me (I have the PS3 version, maybe that has something to do with it?). But this game is not perfect by any meaning of the word, again IMHO.
I'd personally give it somewhere between 8.5 to 9 out of 10. Despite it's flaws the set pieces are epic, it has some of the most quotable dialogue I've heard since Armageddon, and a lot of the moments in the game will probably be immortalized on some websites top -insert number here- video game moments of all time.