I started with 3.5 DnD.
And, tbh, I've seen every iteration since as an improvement. I have affection for 3.5, and I find it fun ... as a charop, char gen game, but my first attempt to DM it was disastrous, and table play isn't as good. Like, it's a game that's more theoretically fun than actually fun, if that makes sense.
4e, sure it was very different, but this system felt balanced enough I enjoyed being on either side of the DM screen. Combat was legit fun to fun, and the game rewarded co-operative tactics. But the character building experience wasn't as good, I find you just pick the powers that match your PC ... dunno, felt a little on rails.
5e, though, synthesized a lot of what I got out of 3.5 and 4e into a single experience, while being a lot lighter and easier to play.
5e24 ... an upgrade, there have been enough quality of life upgrades to make it a better system, but I am left with the thought of "would it have been better to sacrifice backwards compatibility and gone further?". Dunno, but I'm playing a Wild Magic Sorcerer and having a ball with the new system, so I'm glad it's here.