I say BIONICLE isn’t just a good story, it’s a great story. I’ve thought long and hard about various aspects of it in recent years, and it continually remains one of the most comprehensive and exciting stories I’ve experienced.
One of the greatest attributes of the story was its tendency not to shy away from serious problems and serious stakes. It wasn’t just fluff or a shallow action flick. 2004 and 2006 are both great example years for this. The Toa Metru had some serious teamwork issues, and Vakama’s crippling self-doubt humanized him beyond your ordinary “save the world” hero (not that saving the world is bad, but if that’s the sum total of the character’s personality… that’s not a character). In 2006, the Piraka were legitimately savage villains that drove the story relentlessly. They weren’t even dark for the sake of being dark (as with many of the villains–another general aspect I love about BIONICLE), and their “team” dynamics are among the most unique antagonist interactions I’ve ever seen.
BIONICLE villains are actually consistently amazing to me due to their varied motives, dynamics, and methods, but that’s such a massive topic for me that I won’t bother opening it further.
Another interesting aspect that I haven’t thought much on is BIONICLE’s near-seamless multi-faceted approach to the story. We got 2001 through Takua’s eyes and the Toa’s eyes; we got many later years from the perspectives of the main characters, but also from those of side characters through serials. It’s an approach I haven’t really seen in taken to any other story, and is uniquely suited and enhanced by BIONICLE because it was capable of leveraging so much media. It really built the depth of the world, even to experience a year’s story in a different way from its canonical transpiration–VNOG, for instance, puts a new and deepening spin on Voya Nui.
Now, short answer questions:
Yes. I think 2008, 2006, and 2001 were the strongest years storywise (in that order, strongest to less strong), and 2009 and 2005 were the weakest (2009 being weaker). 2009 in particular had a boatload of potential that was never really capitalized on, in addition to throwing the story into a different location that didn’t exactly fit tonally with the preceding eight years. 2008, meanwhile, followed very well on the previous two years and presented a dramatic “conclusion” to the large-scope Ignika arc.
I tend to prefer the books over the movies, but the writing is objectively pretty generic. Again, though, I think the use of different formats enhanced the overall story.
Most of the villains were fantastic. The handling of a proliferation of characters without most of them becoming stale or same-y was fantastic. The heroes were sometimes less interesting, though, and various digressions (2005, Empire of the Skrall, etc.) distracted from the overall story.
I mean, yeah, it was effective marketing. But I think the merits of the story stand for themselves, too. The balance of multitudinous viewpoints and characters, the structure of the world, and the buildup to the ultimate victory of Teridax at the end of 2008 are all well-executed and exhibit interesting storytelling methods that can be studied and learned from, I’d say.