I finished my 4th Dragon Quest game. My current order is 4, 5, 6, and then 8. Though I did get 80% of the way through 5 before all of that, then beat 4, then actually beat 5. Practically useless info, but I think being honest about my experiences with the games is fun. One to couple sentence review of each before I talk about 8:
4: This game is fine. The epitome of a 6 out of 10. I dislike the pacing and none of the characters are remotely interesting frankly. FF4 clears.
5: This game fucking rules. Holy shit. Monsters, wives, kids, and horse freaks. Love it. I don't know if I'd play FFV or this again. They're both incredible.
6: This game sucks. My least favorite thing in any RPG with classic leveling systems is punishing you for grinding. If you overlevel in DQ6, you stop gaining job points. Why!!! There's no reason!!! Let me overlevel!!! It's fucking Dragon Quest man!!! I played with a hack to disable that because I just wouldn't have played it without that. Fuck man I'm getting angry. I like FF6 A LOT more, but it honestl y has a similar anti leveling thing in the espers being necessary to really maximize your levels but you don't get them till the last third or so of the game. FF6's story is awesome though. And DQ 6's story sucks. Fuck this game man.
8: Now here is a real fucking video game. For starters, I played the 3DS version, which has a host of cool features. The most notable of them is that random encounters are actually wandering the field so you can dodge them and selectively change what's around you just by panning the camera. That alone for a DQ game, where grinding IMO is such a substantial part, much much more enjoyable. In my humble stupid opinion, grinding is dumb, and letting me optimally grind my way through the game is way more enjoyable. Mechanically, I really like the party layout. Despite my afforementioned love for FF5, I generally don't prefer job systems in my rpgs. If they are there, I like limited scope paths down the job system, ala Fire Emblem: The Sacred Stones. DQ8 is particularly great in this regard with its skill system. Having 5 set paths that you can go down is quite nice. I followed a limited guide to make sure I was setup well for metal slime hunting and not using the shittiest weapons, and I was off. Each of the characters fit nicely into the DQ archetypes of hero, big guy, cleric, and wizard. Even then there is a bit of flexibility in that, as Angelo gets some nice damaging spells, Jessica and him share a number of the buffs, and Yangus even gets some minimal heals. It's not really needed most of the time, but it is still quite nice. The story is... fine? It's better than the other games, in that it has a central through line from moment one, dropping you into the Hero's quest without any hullaballoo that the games love to throw at you. I think I'm sad the characters don't really have any noticeable character development past their introduction, but they are fun cartoon characters to slam into monsters till the last bit of gameplay.
DQ8's real charm is that it actually evolves the idea of what a JRPG could be while still staying classical. The world map is not as scaled down as other games; you're really running your whole ass from point A to point D over and over again. At times it was tiring, but I really admired how much it made me feel like I was in a setting. It's hard to capture that feeling, especially in a PS2 game. I do think boat travel sucks, and the bird is a little unwieldy. I only used the tiger literally once, so I don't feel good about commenting on it. Actually twice, shows how much I remember.
I didn't do the final side content. The dragovian trials or whatever. The game is good without them. 9/10. Quintessential rpg.