I'll give this a spin, sorry if I offend/get a totally wrong impression of you.
Loose_Lips: A man who loves his shoegaze. Also has a knack for finding very obscure, older music. His tastes deviate a lot from this board, and his posts related to music often go under-replied because of this which is a shame.
CanwllCorfe (how DO you say that anyway?): Sometimes it's hard to believe you're only a year older than me. Your favorite bands are so obscure they make my last.fm charts look like the top 40. Although our tastes are very different, I trust what you recommend to the board as it has all been top-notch in my book. Be it gentle ambient works or black metal.
( . Y . ) (boo boo): Famously a prog fan but there's more underneath that guise. He may rag on stereotypical indie a lot, but he will give most anything a chance and may surprise people with what he likes.(I mean, did ANYBODY see NMH and Wilco on his Top 101 coming?). He needs to give another Nick Drake album a shot though.
Anteater: I don't think there's anybody on this board who can find obscure prog and Japanese bands better than this guy. If you're into music that's sounds like it's from bizarro-world and he posts a link, you'd best click on it. However, he does tend to treat things a tad objectively but with all the good music he posts I can live with that. =)
khfreek: We recommend music to each other often, so we share many favorite bands and artists. However his roots are more firmly planted in punk than mine are, and he can take guttural vocals better than I can. Needs moar 'girly' music though.
Fasho: From what I can tell, he came to MB and immediately started expanding his taste. He checked out every genre, giving everything a fair listen, then ultimately found his niche in indie and its affiliations. His tastes are still very diverse though and you should never assume that he doesn't listen to something as he may surprise you.
Awwsugar: When you look at her posts regarding music, it's hard to put her in any sort of stereotypical box. She listens to a contrast of radio pop and more obscure music. So while she may post about Lady Gaga, she'll also post about Sigh or Sigur Ros. She likes what she likes and isn't going to compromise to fit into any sort of group and I can definitely respect that.
I may do more later.