I did this site as a favor for a friend. As a teacher, his current and former students ask him questions often. He is able to post his answers on this site for all to see.
I chose to do a custom Wordpress theme on this site. Because it was a “favor” site, I just did the graphics myself, instead of paying a designer like I usually do. He likes it. It looks great, and fits his needs well.
My favorite custom feature is a list of links at the bottom of each post page. It contains all the other posts in the current category.