You post a topic, list, category, whatever, in my comments section. (examples: "5 Things Mal Reynolds Wishes He Never Saw on Serenity", or "5 Spells Willow Rosenberg Wishes She'd Never Cast"). Then, in a separate post, I'll post the answers to all your Top 5 ideas, according to me. Serious or fun! Then you post this offer in your own journal, if the mood takes you.
Go for it.