I thought DQVIII was more of a step backwards than IX was. I hated the personalities of Jessica and Kukule/Angelo. Yangus was alright though. Trode was pretty cool as well. And I thought the town stories of VIII were inferior to IX's.
IX isn't perfect, but it did a lot of cool things.
If I had to pick an order for the DQ games, I'd say:
Dragon Quest VII: It was pretty much the sum of every Dragon Quest to that point. You have an awesome main cast. The characters you meet in the various towns are excellent. The town vignettes themselves are the best in the series. And the whole package is so meaty
Dragon Quest III: It is the Goldfinger of the Dragon Quest series. Yeah, there were games before it, but it was with DQ3 that the series found its voice. So many style, plot and gameplay conventions came from this game.
Dragon Quest IV: This used to be my favorite, but my distaste of the US DS version has pushed it down a little bit. Awesome cast, awesome monster designs. AWESOME FINAL BOSS. Some of Sugiyama's best work was in this title, by the way.
Dragon Quest IX: The main game was too easy, but the post game was insanely addictive. Between my imported Japanese version, and my US version, I've probably logged about 500 hours in this game. It's way more fun with a friend, and I feel US audiences probably missed out on this fact. Still, lack of monster variety brings it down a bit.
Dragon Quest VIII: Yes, this game was beautiful. It's STILL the most beautiful game in the series, nearly ten years later. But besides its beauty, the whole game felt inferior to DQVII, for reasons I've already mentioned. Best world map ever though.
Dragon Quest VI: Interesting plot and gimmick, even if it was done in other games first. Probably my second favorite cast in the series. It's a shame the DS remake was more of a downgrade. VI deserved a better remake then what we got.
Dragon Quest V: Everyone loves this game, and I can see why. It's a very touching story. Probably the most central story-focused game in the series. But for me, I play Dragon Quests for the side characters and town vignettes, and in this regard I found the game lacking. I am also find this game to have some of Sugiyama's worst work, world map theme aside.
Dragon Quest II: We're getting into archaic territory here. Sugiyama really nailed that world map theme in this game. Still, the plot and towns are pretty hollow, compared to later games. Also, Cave to Rhone can go to hell.
Dragon Quest I: Don't get me wrong, I like DQI a lot. It's a classic. But I'd be hard pressed to recommend it to anyone. It's just too old.
As for Handheld vs Console, Single-player vs Multiplayer. I think there is room in the world for both types. I'm more of a handheld gamer, to be honest. I hate feeling locked down like I do when I play consoles. That said, I think I want XI to be a console release, single player. Preferably on Wii U, so I can play it off screen.