(Edit: ummm sorry wall of text ish here)
(2nd edit: I really hoped people would post their favorites too. I guess our community isn't large enough for this type of thing yet)
For me Dragon Quest 3 is my favorite not only out of Dragon Quest but my favorite game ever. The NES version has a special spot in my brain. It got me addicted to grinding class changes. While you can farm seeds to get every stats to maximum if you really want, there’s an arguably shorter path in that you can take advantage of the class change systems quirks. This would mean maxing out some stats at half their potential, but that is still a lot less time using seeds if you want to cap out everything.
My cat had died just before my birthday, I was real depressed for weeks. I’d been renting games on Fridays to keep occupied on weekends (this was late 80’s/early 90’s, rentals were still a thing). School kept me busy the rest of the week and I'd either be at a friends house or at the library after school. But I’d often spend almost my whole weekend gaming. My mother noticed I was spending almost all my money on one in particular and knew I was super down coz of the cat, so she surprised me by prepaying 3 weeks worth of it. She’d later realize she could have bought it outright but that’s a whole other story. That game was Dragon Quest 3.
So I beat Zoma. I was now able to remove the Hero from the party. “Could I create a character more powerful than the Hero class?” I wondered… The Soldier(Warrior) gets pretty good weaponry even if I can’t equip the specialize hero’s gear. The Hero can’t class change, so he can’t gain the extra spells from Pilgrim(priest) and Wizard.
I could take the spell casting classes up to get all their spells easy enough, but each class change divides their max MP in half, and the other classes don’t gain any MP at level up. I could start with a Fighter for high agility, but once I switch to Soldier I won’t be getting much. At most I would get 1 per level up and even that would take a lot of save scumming (this is because the NES game reduces stats growth when a stat is already high for your level). So I was going to have to plan carefully, learn from mistakes along the way and re-level some of the same classes twice to get my stats balanced out.
Along the way I learned this version of the game had some bugs I could both get bitten in the rear by (happened) and also exploit (also happened!) In particular I found out if I had high INT it didn’t want to cough up any good max MP gains. But if I had low INT and then my level up gave me a bunch of it, that usually also came with a big dose of Max MP. That told me hold off on using int seeds later for sure. in fact I resolved to not use any seeds until I was both on my final class and had pushed it as far as I could by leveling alone.
The end result: a soldier with 255 strength 141 agility 255 vitality 139 intelligence and 180 luck, with a max HP of over 600 and a max mp of 299. And I had all the non hero specific spells. And a meteorite armband capped out the agility. I could start maxing the rest of the stats with seed farming OOOORRRRR I could make 3 more like him. Insert evil laughter. I never did get around to maxing everything out with seeds, but I did get a fighter and a 2nd soldier crazy stat'd like this. The fighter was able to 255 strength agility and vitality, at the cost of not having such nice equipment. And a sage (hung onto that book forever!) that came pretty close.
I hope whoever rented that cart after me took a good look at that save file before wiping it, and if not I hope you are reading this :P
Thor(Soldier) Aaron (Fighter) I forget the 2nd soldier's name and the Sage's name but the hero would have been named Ace.
I wound up buying the game later and starting over. On every remake. Even the mobile ones. Every so often I start over again and experiment optimizing my class changes to reduce save scumming dependence since level ups always have a little randomness to them. I'm looking forward to the new version dropping in November and adding abilities to the mix - hopefully I can retain some if not all of those in class changes as well.
On remakes my "final form" so to speak tends to be thief. They get such good gearing options now.