After all these years, Sims 2 is still my favorite, and unless they make a Sims 5 with the open sandbox and gameplay without restrictions it will always be my favorite. I'm probably what you'd call a "dollhouser" so the Sims 2 fits what I prefer for my gameplay. I like to rotate through different families, and play ALL of them through multiple generations. I can easily see their emotions in how they react to situations and interact with other sims. I don't need some silly toolbar that rapidly cycles through all the emotions. The genetics are incredible. I love seeing how a facial feature passes down through the generations. I love how they have memories, and that those memories will affect how they interact with others for a long time, sometimes their whole lives. I can have a wide variety of lots in my worlds, residential and commercial. I can place them just about where ever I want. I rarely have to worry about running out of room.
Sims 3 is fun, but it seems to be a bit restrictive for when I want to play a different family in the same save. It's possible, just a bit more hoop-jumping. So I'll play Sims 3 when I'm in the mood to stick with one family, because I like the other features. The worlds are gorgeous, and all the different things I can do in the game are a lot of fun. One thing I wish we could nerf entirely is the reputation system, or at least tailor it to our needs. If my non-committal sims are involved with other non-committal sims, there should be no hit to their reputation.
Sims 4 I have had a love/hate relationship with, and lately I've become apathetic about it. They got on my bad side from day one with the excuses about leaving out toddlers, and the shabby treatment family play gamers were subjected to. It's great that they finally gave us toddlers, and they're extremely well done. By far they are my favorite age in Sims 4 because of how much detail they have. But I feel like they let too much time go on before toddlers were released, and the way family play gamers were treated was quite unacceptable at times. It was really appalling and it has tainted how I feel about Sims 4. There are things I like about the game. The toddlers, they really blew me away. So much detail. I don't mind the art style or graphics, I'm ok with it. Since I am primarily a Sims 2 player, I don't mind the loading screens. I'd just be a lot happier if those loading screens allowed us to have Sims 2 sized worlds and populations. I like the club feature, except for some minor complaints I think it's well done. But otherwise, I don't feel like I "rule" in this game like we're supposed to. I think an off-hand comment by a guru hit it the nail on the head for me. He made a remark about how they wanted us "to play the stories we want you to play" or something like that. I'm not interested in their stories, I want to play my own. And since Sims 4 restricts my creativity, I tend to play it only once in a great while. The "nope, you cannot do that" and the checkbox grind make me frustrated quickly and I quit.
Since I finally have a few days off, I've been thinking about what I want to play. Do I want to check out the dogs & cats more in Sims 4, or play out a story in my head in Sims 2? I have a feeling I'll end up spending the weekend on Sims 2. It's the one that keeps my interest.