I love this game - the original is still the best in my opinion

It's interesting because each entry in this series as very different despite being so similar in so many ways.

The original was a grand space Opera. Playing it left you with this mystified feeling. You loved going everywhere just to explore this wonderful galaxy.

Two cut WAY back on the exploration and started throwing stuff at you fast and hard. The story was gritty and even a little horrifying. However, if it was left strictly to this story and setting, two would have been very different and it easily had the best cast of crew mates. Garrus returned, you got to meet up with Wrex (if he was still alive) and a host of new characters including Mordin, Grunt, Legion, Thane and Jack were added. Add on top of that, Zaeed and Kasumi (who was part annoying and part fun) and you've got the best ensemble cast in the series and possibly the best outside of a Final Fantasy game.

Mass Effect 3 returned to the grandeur of the original except in a much more focused way. Rather than having a focus on exploration, discovery, and a feeling of distant myth, you're presented with the culmination of a legend. Before you start playing, you know what you are up against and I'm sure almost everybody is sitting there going "Ok, I understand what I have to do and even the tools at my disposal to do it but... how in the hell can one person do THAT?"

And then it hits you... You're Commander Shepherd. There is one more tool that you are forgetting. You're the biggest badass in the galaxy and the galaxy respects you because of it. And you set out to use all of your cunning, skill, and credibility to pull it off.

To me, Mass Effect 3 is essentially "What would happen if James Bond needed an army? Would his incredible breadth of skills, diplomacy and deadliness be enough to bring the entire world (including the Middle East and North Korea) under a single banner?"

And that's why it is my favorite. You are the only person to ever succeed in the countless attempts made cycle after cycle. How can you not feel like a badass? Though it just barely beats out ME1.

Number two was my favourite :-D