Monobook is a skin that, although not widely supported by Wikia any longer, is nice and customizable. However, not many know how to customize Monobook so they don't use it.
Recently, a few users and I have created a wiki so that users who would like to use Monobook can have a nice theme on that wiki.
If you have a theme request please make sure to read the guidelines on requesting the themes.
Once you have read our guidelines and you have a clear community consensus, request your theme here.
With MediaWiki 1.19.1 on most wikis now, there might be some problems that have happened when your wiki was upgraded. If you need any help figuring out or fixing those problems, drop a message at Theme Fixes forums and we'll get right to it!