Nice to play but probably not as good as the previous two
Overall, this game is a nice end to the series. We wrap things up in the universe by dealing with the reapers. The original ending was bad. I didn't take it as badly as what was in the media but looking at the EC ending now, I can't help but feel how terrible the original ending was. The EC ending is what we should've got in the first place. It's not awesome but it does the job with a satisfying conclusion to the game. There some questions left but I don't care anymore. Will I buy a new ME game.... well, if Shepherd is not in it, then probably not because Bioware screwed it up this time along with Dragon Age 2.
I did feel like the quality of the game dropped a bit, as in ME 2. Couple of bugs but nothing to complain about. The biggest addition to ME 3 is the multiplayer component which I still play as it is a lot of fun. Rarely are there lag issues even when I play with players from around the world, therefore I feel that they got this part right.
If you've played the previous two games then yes, you should play ME 3. If you haven't - I'm not sure what to say because you might get disappointed with ME 3. The story was really good but it deteriorated in ME 3.