I started under second edition rules, but really cut my teeth under third and 3.5 edition. We are currently under fifth edition (5.5 really with the new revised books coming out). 3.5 was my ideal Dungeons and Dragons. It may be nostalgia talking, but I've always felt it hit just the right sweet spot of moving away from some of the clunkier aspects of earlier editions (over reliance on having to consult tables, saving throws that were all over the place, THAC0, etc.) while codifying the d20 system and giving you a lot of flexibility with your classes. I liked all the classes, prestige classes, and multi-class options. It required a lot more work from the player to keep track of things, but it gave a deeper experience. Feats were unquestionably better in 3.5 than fifth edition, as well.
Fifth Edition streamlined things even more and made them very accessible, but at the cost of depth and complexity. I was playing Pathfinder mostly during fourth edition* as it used an open license fork of the 3.5 ruleset and gave it even more depth. I'd honestly probably be mostly playing Pathfinder still if it hadn't lost so much market share when fifth edition hit.
Fifth edition is fine. It's more narratively focused and less concerned with the crunch and rules minutia of 3.5, and I do miss that, but it's still D&D and I still enjoy playing it.
I've got some retro clone sourcebooks for second edition that I want to run a game for, just to show the newer players what we had to deal with back in the day.
*Fourth Edition was a short lived and disastrous attempt to completely overhaul the game and incorporate MMORPG-style elements on the tabletop. It was a huge fiasco and most players migrated to Pathfinder during this time. When Fifth Edition hit everyone went back to D&D and Pathfinder fell off pretty hard.