I've played since AD&D 2nd edition first came out, and probably still think that's the most fun to play. I did play 3/3.5, but felt like the some of the charm was lost. It was more effective in ways, and obviously designed with better conversion for computer games with the way it handled math. But between the futile attempt at trying to overly balance the system and the *very* spotty situation with 3rd party material quality, it didn't really stand out to me as all that great. Pathfinder was more of the same.
One thing that's also worth noting, for my perspective anyway, is the shift in community that happened during 3/3.5. Back in the TSR days, there wasn't really a huge push for people to try and min/max the system too much because it just wasn't meant to be "balanced" like that. Furthermore, coming up with options for min/maxing or even just character ideas, was largely the result of normal socializing with your close friends and maybe some guys at the gaming store. Everyone probably heard of someone who knew a guy that knew a guy running around with a -10AC Holy Avenger Paladin who supposedly rolled all 18's or something, but those were as good as urban legends.
When WotC took over, the internet was really starting to explode. So not only did you have a system ripe for exploiting rules and feats and items and class combinations, but you had a massive stage to disseminate that information. And it's gotten better/worse ever sense.
I feel kind of sorry for people that want to get into the game, and start looking up "character builds" like it's an MMO or Skyrim. I understand that's where they are coming from, but so much complaining really stems from things like totally min/maxed characters setting the bar for class balance in a vacuum. Like my party has a ranger who's doing good damage. We don't really track and compare totals or anything, so I can't say he's on top or bottom or wherever, but he's happy with the character and feels like the theme is really cool and he has an important role in the party and story. Same thing with really everyone else, to be honest. But on the weekends where we get a new player or someone hanging out who normally plays adventure league or runs with hobby shop games, the dynamics of the group really change for the worse. It's like this sudden focus on efficiency above everything else, including roleplay.
So although I currently play 5e, and will continue to do so for a quite a while (it's a fun system), I do very much feel like the best years have long passed because of how the community has and communication has shifted the focus *away* from the roleplaying aspect.