Well, if reader action is any indication, my new WIP Harry Potter/Highlander crossover, By The Sword, is far and away my most popular story ever! As of today, 16.48% of those who visit the story on fanfiction.net either leave a review or add the story to their favorites or alerts lists. Compare this to only 6.64% for the next most popular story, or only 3% for my most visited story. Wow. By the sword may not have the most raw hits, or the most reviews, but clearly the readers like it.
I have this nifty excel spreadsheet set up to automatically monitor my FF.net stats and convert them into useful charts. Sometimes, I just can't resist sharing the results. :)