I started getting into Mass Effect for real about a three weeks or so ago. Before that I tried playing ME1 twice, once when I borrowed the game from a friend but hardly played it and again last summer when I logged about 6 hours total. Anyway, I got into it properly this time around, starting with the first Mass Effect and have been playing it plenty since.
With ME1, I was really just interested in completing the main story so I didn't do many of the side quests at all. I enjoyed it anyway, found it reasonably fun and sunk about 22 hours into it.
Then I bought ME2 and just couldn't stop playing. I liked the crew (Garrus is my homie for life but Thane is awesome), like actually all of them, even the ones I didn't like at times like Miranda and Jacob. I had more fun completing the side missions that I thought I would have and was thus pretty well prepared for the final mission. I managed to get my entire crew through it, which was pleasing, as I was constantly second-guessing every decision. Loyalty missions were fun and intriguing. Kinda sucked Miranda turned into a bitch once I sided with Jack (I couldn't Paragon/Renegade my way through this mess). I have lots of good things to say about ME2. I think I spent roughly 35 hours on it.
And now I'm on ME3, about 12 hours into the game, I'm enjoying the experience, but it really feels flat compared to Mass Effect 2. The game is legit fun to play and all, but there's something about the atmosphere of the game that makes it feel a lot less fun than ME2. That ragtag crew ambience is missing. I hated working for Ceberus because it was obvious they're evil sons of bitches, but at the same time, I really enjoyed that part of the story. Now with my entire crew scattered in ME3, and hardly anyone of them coming back, the experience feels hollow. I also really don't like the redesign of the Normandy SR-2. It was supposed to be retrofitted to be better, but I think the previous design was much better. And another thing, I really don't enjoy the missions as much as I did ME2. They feel so much more like checklist chores now to boost my War Assets than for personal satisfaction on my own part. On top of that, ME3 doesn't feel like a full game because so much of the good stuff is tied to DLC - DLC I don't feel like paying for unless it's on sale.
I dunno, I'm only 12 hours into the last game, but I think it's 2 > 1 >3 for me in terms of quality of games.
I'm glad I finally jumped into the franchise for real though, it's been a blast thus far, all things considered, and I'm actually looking forward to this supposedly terrible ending that pissed off the fans.