This post is here to house SEDE (StackExchange Data Explorer) queries relating to this site. Originally spawned from this thread.
Queries are categorised below depending on the data they look at. If you have written a query and would like it added to the list, just edit it in in the correct category (if you feel there is no category, create one). Please do not add new answers for other queries. I've made the answer CW so most people can edit, however if you have insufficient reputation and would like your query added, leave it in a comment below or talk to someone in chat.
If you feel like you can improve on a query, just fork the query using the link in SEDE and make your changes. You can change the link in the answer when you're done.