yoshino: I've finished all DraQue games except the 10th(MMO-RPG, duh) and the 7th one was the longest game and sometimes a bit boring by endless sub quests.
But I played the PS1 original version, and I've heard the DS version was enhanced from the original quite a bit.
By the way, the 8th one is my favorite in the series with 3rd and 5th.
Personally, I actually consider the 5th and 8th games in the series to be my least favorite. My favorites are 3 (remakes only) and 6 (original version). In any case, here are my issues with the games I like less:
DQ5:
* Game forces you to play a male character. (This is notable because both DQ3 and DQ4 allow you to make the hero female.)
* Game is too heteronormative for my tastes. You *have* to enter a straight marriage to continue the game at one point.
* Game is sexist in its handling of the main character's children. The son becomes the legendary hero and gets unique (and powerful) spells and equipment), while the daughter has nothing unique about her. (I note that DQ4 had a *much* better handling of female characters, including one who *isn't* a spellcaster.)
* By DQ standards, the game is way too cutscene heavy.
* Getting certain party members is *way* too RNG dependent. (The original has an obscure trick that lets you guarantee monster recruitment, but that was taken out in the remakes.)
* The original version limits active party size to only 3 characters. What was the reasoning behind that? (Incidentally, the combat system works properly if you hack a save state to increase the party size, but the game will glitch outside of combat.)
DQ8:
* Game, again, forces you to play a male character. (The only DQ games I will excuse from this criticism are the first two.)
* No control over your party. You get 4 characters, and that's it. Furthermore, the party isn't gender balanced, and the characters aren't balanced with each other (in particular, Yangus is underpowered and Jessica is overpowered; why should the mage's physical attacks be stronger than the brute strength character's?).
* Skill point system requires you to make irreversible choices in character development at a stage when you don't know which choices are good. It also makes it nearly impossible to teach characters new types of abilities later on. The class systems of DQ3, DQ6, DQ7, and DQ9 don't have this issue. (DQ9 lets you get extra skill points by leveling up other classes; DQ8 lacks anything similar.)
* The game plays more slowly, as battle animations are slower and there are also load times (a problem that earlier DQ games didn't have).
For completeness:
DQ3 original:
* HP and MP growth handling is horrible; to give you an idea of how bad it is, I note that the Seeds of Vitality and Intelligence will actually hurt the character's HP and MP growth, rather than helping it. (While it may look like I have only listed one flaw of this game, it is actually a dealbreaker for me. Fortunately, this was fixed in the remakes.)
DQ6 remake:
* Must play as a male character (the original has this issue, but by my policy I need to mention it as a flaw)
* Can no longer recruit monsters (could in the original DQ6)
* Balance was adjusted for the worse, not the better. Vacuum (mistranslated as "Thin Air"), one of the most useful skills in the game, was made stronger (to the point of making enemies with this skill more dangerous than they should be), while Madante (translated as Magic Burst), an ability that was already impractical due to its high cost (all of the caster's MP), and was the only thing Barbara/Ashlynn really had going for her, was made weaker to the point of being entirely useless.
Edit: I should point out that I actually do like the original Dragon Quest, especially given how differently it feels compared to most other JRPGs; it feels like it could even fit in a different subgenre.