Which ideas are the most worthy of expression?

For a philospher, better yet an artist, which ideas make for the best communication. That is, which ideas command the most interest and are worth exploring, then sharing with others. Are some ideas more worthy?

There are some coarse subjects that people flock to, and much of this is called low brow enterainment, but are there some borderline subjects that you think extend in both directions: low brow and high brow?