Wow. This is a pretty big question.
The main big names on my list are the BZP admins, for their dedication to the site, and Bionicle island (founder of Kanohi-Power.com) for creating one of the first main unofficial Bionicle news sites (unfortunately, he's looong inactive).
The BS01 people, specifically Crystal Matrix, Pekel, Swert, Dorek and Erebus; for making the best Bionicle encyclopedia.
The TTV group is pretty well known for Bionicle fandom.
Also, DeepBrick and RedQuark were dedicated to uncovering the lost LOMN game, so they're here also.
The Bionicle fanfic writers, including TNTOS, Steelsheen, GaliGee, Bonesiii, and Angel Bob.
The Bionice Storyline people, specifically bonesiii (also a fanfic writer). I'm pretty sure it's missing the point if I say GregF, but he is a BZP - a fan site - member, and one of the biggest contributors to the Bionicle storyline.
This went from "The Biggest Name in the Fandom" to "who is best fan" quicker than I expected.
Anyhow, aside from the obligatory TTV guiz (aside from myself) that I do see mentioned, I have seen DV mentioned around ( ), Black Six as well, and SPIRIT. I'm aware a guy on Youtube name iBionicle is fairly well known, however he is inactive. Kelly, of course, is also a big name, although people don't know his history as well. I also known VBBN is well known and recognized by Lego, and he's active. All in all, I don't see a whole lot of BZP people mentioned.
iBionicle was an amazing YouTuber and a big part of Bionicle fandon, if you ask me. His stop motion was fantastic, as well as his MoCs.
If I think of more names, I will add them.
Edited by Underscore, Mar 27 2014 - 04:18 PM.