I guess I'll give this a try:
Bulldog- Well, he was one of the first MB members to talk to me and he along with Rickenbacker referred me to the site. He might just be my favorite member on the site...
Rickenbacker- I have a little secret about this guy:
I've met him in real life. While he gives off a rather mean impression on MB I think he's actually a pretty nice guy.
jackhammer- Of course everybody knows him, he seems like a really nice guy. I really like his diverse musical taste, and although I checked out his last.fm and we have "Low" compatibility, I never seem to disagree with his taste.
booboo- I remember on the first day I joined, I saw him and at first I thought he was rather childish in his posts. Now that I've been here longer and, while I havn't talked to him much (our musical tastes are not really that similar) he has struck as actually an intelligent person who gets a lot of grief for no reason.
Neapolitan- I have mixed feelings about him. We don't have much in common musically, but he does seem like a pretty nice guy. Apparently people think he's a troll (?) but I disagree
FreeBaseDali- I've only talked to him in the shoutbox, but from that conversation and from his posts, he seems to be one of the smartest members on the site, who maybe needs to watch the insults sometimes.
TheBig3KilledMyRainDog- Unfortunately most of the posts I've seen by him seem to be pretty mean...
Kayleigh- Well I seem to be with most people here when I say that I can't stand her musical taste, but other than that she seems to be a pretty nice person, who's excessive smileys can piss me off sometimes
PissMeOff- I don't really understand his username, because he seems to be one of the least offensive members on the site. He likes the Smiths (always good) and is generally very nice about things.
Dreadnought- Everyone seems to agree that she's pretty, but I've never seen any pics of her, and I hardly ever see her post
UrbanHatemonger- He is one of the most interesting people on the site to me. Sometimes he's nice, sometimes he's mean, but overall very smart and and good taste in music
Lateralus- I quite like her taste in music, and she often says pretty funny things. Also, her Australian accent is kick-ass
Right Track- A very moddy mod. Meaning, unlike some of the others, I'll actually see posts where he's telling people off for spamming or something, not just ragging on them for having slightly different music tastes than him. He seems like a really ni ce guy.
Antonio- I really like him. Really nice guy, actually plays an instrument, and I mostly agree with him musically
Well those are only some of the posters I've seen. Overall of course th site is awesome, and I look forward to sticking around