I recently got the Legendary Edition of this and went for a full play of the whole trilogy after all these years. Originally, I had played all of ME1, ME2 with all free DLC's but none of the paid ones, and I never got to play ME3 at all. I was curious how the games would fare for me after all that time. I won't go into the "is it an RPG" discussion, as I think all has been said in that regard. Personally, I don't mind that much, given RPG's are just one of the genres I enjoy to play.
ME1 got the most changes in this edition. My memories are hazy, but I had the feeling that the gameplay got a bit smoother. Lifting the weapon restrictions makes the game less of an RPG, but I certainly liked the changes this brought to combat. I didn't expect to enjoy the replay as much as I did. Disclaimer: I never disliked the Mako and had always found those sections quite fun, apart from some of those planetary explorations where the terrain was just bad. Another commonly mentioned annoyance are the elevator sections, but I think those pale against all those empty corridors that probably hide the loading. Other than that, the game was still fun and interesting, even though it's formulaic Bioware of old and very close to KotOR 1 in many aspects. The only DLC included was Bringing Down the Sky, and this one just fits organically into the game. Pinnacle Station DLC was available via a mod, but I quickly noticed that its non-inclusion in the package wasn't a loss. I didn't bother with it more than for a short test. As an aside, I enjoyed the often very subdued music in this game very much, which perfectly set the mood for me. So, yes, this game fared better than I thought and surpassed my memories.
I went on to ME2, and this one went into the opposite direction. I remember I originally thought I liked this a bit better than ME1, but I certainly wouldn't say so nowadays. This may be a replay issue, as the trilogy starts drifting into character-driven gameplay. The main part of the game consists of collecting your team and doing their loyalty missions. I think the replay made clear that the game had more team members than character concepts, and that redundancy becomes very obvious when you already know where everything is headed. I had never played Kasumi (was a paid DLC), and at least she had a fun mission, even though I don't think she's an overly interesting character. A bit too useful in combat though. After a while, all those daddy issues start wearing down on me. I knew DLCs like "Normandy Crash Site" (pure fan service of the rather boring kind), Zaeed (actually not a bad companion quest) or the Firewalker DLC (more gimmicky than the Mako - bah). Of the "new to me" DLCs, Overlord was okay, even if it featured that vehicle and a - to me - somewhat confusing map, which was balanced out by the main plot point. Arrival was "Bringing Down the Sky" part II, this time with forcing you to make the opposite decision. It's kind of a nice bridge to the next game, but I can't say I liked it overly much. "Lair of the Shadow Broker" definitely was the best of the bunch for me. All in all, this sounds more negative than it should, because I still liked the game very much, even though it didn't match the view through my nostalgia glasses.
On to ME3 it was. I don't exactly know why I never played this. It was probably a mix of that ending outcry, the multiplayer aspect and some of the DLC decisions that soured me on the prospect of going through this. The Legendary Edition now has no multiplayer, includes the Extended Ending DLC and has a few ending conditions reworked. I'm aware of the point that managing your expectations has a big influence on the personal perception of a game, so I have to use this as a caveat: I knew the endings were bad. As such, I had more of an "getting it over with" attitude towards that part of the game, and it didn't influence my overall verdict very much anymore. All in all, this game pleasantly surprised me. As I said, I won't go into the "is it an RPG" discussion, as that doesn't really matter that much to me. I was honestly surprised how long this game was. I can't tell for sure, but I had the impression this was the longest game of all three. I was also surprised, how much the game made of almost every tiny decision you made during gameplay. Even seemingly random conversations you picked up when you passed by NPC's could have an effect on your war assets - sometimes, though rarely, even negatively, depending on your decisions. Of course, it's a bit disappointing to see how this rather complex system of collecting points ends in a red/blue/green decision, even though there are quite a few permutations of those endings with regard to NPC's or the game world. There's also the question whether decisions from the last two games should feature that prominently in the third installment, but that's probably a good thing if you are in the "choices and consequences" camp.
One of my other original issues with ME3 were the DLC's, as mentioned before. "From the Ashes" was clearly cut content that was sold separately on day 1 (or close to it, can't remember). Javik was so intricately woven into pretty much all game missions that this becomes quickly obvious. Just compare that to DLC companions of ME2 (Zaeed or Kasumi) which have most of their unique game comments in those Normandy talks. Javik on the other hand has lots of unique dialog all over the game. I don't think this would have been done if that had originally been planned as DLC. Then again, this was non-issue now, given this is now included in this edition of the games. Omega and Leviathan were both enjoyable, and the Citadel DLC was pure fun. Lots of fan service, but of the good kind, and a nice break from the rather bleak main story.
I guess I will say at least something about the endings. I tried two of them (not that I hadn't known pretty much all about them already), just for comparison. I had enough points to get to choose between all endings, except of course those that are bad because of lack of points. The clearly favored ending of the game is the "green" synthesis one. It's the only one where you don't betray any of your allies and companions. It also fits the kitchen philosophy of the game overall, pretty straightforward. I also had the option to choose the only ending where Shepard survives, which is the "red" destroy ending (I think this is a change in the Legendary Edition or the Extended Cut). You will have to sacrifice the Geth and EDI in that case. I would have to calculate if you would be able to gain enough points for this if you destroyed the Geth during the respective story mission or whether you are forced to first "save" the Geth and then destroy them anyway. All in all, I liked ME3 much better than I expected. The game had much more effort and polish put into it than I thought. It's a bit hard for me to compare it to the other two, as my opinions of those are refined by a replay, but I'd say it's still up there.
In the end, I enjoyed my replay and discovery of those parts I had never played before. It's still a solid experience, at least if you are not overly concerned over the "is it an RPG" question.