Hi, I know that I am not a regular, but that banner for the poll was just so inviting!
I intend to vote "other", and I will point to certain posts that make many of my intended points for me.
According to the education classes I used to take, it is visually easier for a person to read light colored text on a dark background. This means I am somewhat in support of a dark colored theme, such as the one used for krick's forum. Also, I like the alternating coloration of posts used by the default theme. However, I don't think the green used on krick's forum is very... appropriate? welcoming? I am not sure what word I am looking for, but what I mean to say, is I would prefer a dark theme similar to back n black, but with alternating post colors (instead of just the coal gray used right now). However, instead of having a darker gray to contrast the posts, and green for topics and other things, I think a dark blue should be used, and for boxes like the "Topic Summary" you will see below when you post, those should be a hue of dark blue as well.
I think the color blue will help take some of the "underground" "unwelcoming" and "tight knit" feelings out of the darker color scheme that I agree with Vigo on.
Personally, I would set yabbSE as the default for anyone who is not a member of the forums (thus to maximize the feeling of invitation) and then when they register and log in, their default changes to the darker color scheme I described. If I remember correctly, the Administrator should have the ability to set different defaults for members and non-members.