ME3
Best gameplay
Best level design

ME2 had better characters though and better cities.

Mass effect 3 easily

ME2, easily. Had the best balance of good gameplay and RPGness. 1 had better RPGness, but horrible gameplay. 3 had the worst RPGness, but the best gameplay, though it only improved on 2 a little.

ME2 was brillant, the narrative was so good. It's a masterpiece, it's a real shame Bioware turned into a bunch of SJWs. Their games haven't been as good since they turned pansexual.

ME 1
2 and 3 were just mainstream 3rd person shooters.

While I love ME1, ME2 outdid just about everything from the first. It does everything a proper sequel should. It expands the cast to include some of the series' most memorable, interesting characters, enriches the lore of the universe with some of the most fascinating conversations I've seen play out in a game, created a really dynamic, interesting set up for multiple endings based on mechanics and thoughtful choices throughout the game, and manages to stand alone both stylistically and narratively. There's almost nothing I dislike about ME2 at all. Even the planet scanning, much derided by most, felt to me like a much needed respite from the surging missions.

(ALERT: RANT INCOMING)

Now ME3... Frankly the more time I've spent removed from the series the more I've come to be annoyed and disappointed with its mechanical and structural foundation, as well as its priorities. I have a very long list of complaints with 3 (all excluding the ending, which I'll let other people piss about), but some highlights include my frustration with how the game turns all potentially meaningful decisions and encounters into a spreadsheet, converting moral choice into gameified number counting, anger at the piss-poor writing that takes an extremely nuanced group like Cerberus and turns them into cartoon villains with the Elusive man basically just waltzing into a room and announcing his evil plans after an entire game that skillfully painted them with shades of gray, and the deep despair over the game's audacity to completely eliminate the complexities and depth of the milky way galaxy that Bioware spent so long building up.

We're introduced to a galaxy with long-standing conflicts that have defined entire races of people, and we're supposed to believe that over the course of a game one dude is just going to solve all of it? I mean Mordin makes such a compelling case in ME2 for why the genophage is just, and even if it's something I can find myself disagreeing with on moral grounds, I appreciate that Bioware made these conflicts rich, with well-thought out sides and complex variables. Why then does Mordin just turn around in 3 and say, without any reason at all, that it's time to solve the genophage? Where did his careful, thought out justification go? Is this really going to solve hundreds of years of strife between such powerful groups? Meanwhile you're also solving the Quarians' thousand years dilemma with the Geth with a very simple message of getting along and understanding each other. Like, guys, these issues are far more complicated than that, at least that was the impression you gave me when you introduced me to this enormous universe with enormous problems and enormous history. ME3 makes it all feel very small and inconsequential, which I hate. It actively goes back and eliminates what I loved so much about the series, its depth. And all doing so while basically canonizing the paragon style of play by infusing the game with all sorts of forced emotions and retconned decisions. If you were played as a renegade, sucks to be you! Your gruff, badass, ends-justify-the-means Shepherd is going to feel sad for a little boy and agree that the Krogan deserve to be trusted. It's like instead of presenting equal but opposing sides for you to evaluate and judge (or at least for your character to do so) ME3 is just Bioware preaching to you how it feels everything should end up.

To be fair, the game is still fun to play, and doesn't ruin what has remained my favorite game series (possibly favorite thing). I particularly like the citadel dlc it gave us as a final goodbye, and I was actually impressed by the multiplayer. My complaints are the complaints of a loving fan who cares about the universe they've created.

Mass Effect 2

Mass effect 2 was in my eyes the best Mass effect and the first one which I played last the worst. The third was also a really good game, but I still like the second a bit more.

Mass Effect 1, despite the issues with the combat, it was favorite. Mass Effect 2 had great characters but story wasn't as strong and they cutback the RPG elements too much. I'm not getting into ME3. Least favorite ME game period.

ME 2