This post serves as a master meta post for topic challenge ideas. Please post your answers suggesting topics we can use as topic challenge ideas.
Also bear in mind that
- there should only be one idea per answer so votes would mean something.
- only upvotes will be counted. You're free to downvote answers you don't like, and if we were to choose between two answers with the same score, the one with fewer downvotes will be chosen.
- the votes will be tallied every two weeks.
- suggested topics must be tags with at least 25 questions, or popularly discussed topics (think of a keyword that appears some 100 times in posts here)