Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Some interesting Stack Exchange Data Explorer (SEDE) queries of mine:
Cross-Tag Tag Usage Breakdown A breakdown and usage count of each and every tag used alongside the given tag on posts.
Anonymous Vote Counts and Adjusted Post Scores Ever wonder where anonymous votes go?
Pulls all votes by anonymous users and users without the respective voting privilege and aggregates them by post voted on.
Comment Length Popularity Breakdown Groups all undeleted comments by length.
(Did you know that the most common comment length on Stack Overflow is 61 characters?)
Most Voted on Q & A Posts in [Date Range] Pulls the most voted on posts on [site] in the given date range.
Especially useful for finding the most popular or contentious posts in a specific time frame.
New Comments on Older Posts Pulls a list of "older" posts with "newer" comment(s).
(Probably most useful for exploring site Metas.)