I like several sites on Stack Exchange and use the Stack Exchange drop down list of all sites frequently to hop from one site to another. I notice the ordering of sites is either random or uses an algorithm I cannot see. If I am not at UX then sometimes the listing does not show on the drop down list. Possibly due to too many Stack Exchange sites.
How are the sites on the drop down list ordered?
Why are they not ordered by ones I am active in?
Are you losing views if users cannot find the site through that list?
EDIT: having read the comments on where this should go I believe this emphasizes another issue. If users cannot figure out where questions should go then there is a user interface problem. Let the moderators move this as they see fit