I feel very comfortable editing questions and answers to improve their content. I've been doing that for a while and after asking questions on Meta Stack Overflow and reviewing others' edits, I feel I understand what makes a good question/answer edit and what does not. I am less comfortable in creating and editing tag wikis. On one Area 51 site beta I am participating in, there are hardly any tag wikis, and when I tried to create one, I did a very poor job and my edit was (rightfully so) rejected.
I think seeing some examples of great tag wikis would really help me. What are some examples of really well done tag wikis, across the entire network? I'd really like to see them for a variety of topics, not just Stack Overflow.