It is obvious from these studies that your first four options are not viable and, while Jello wrestling is a whole lot of fun to watch, it's no fun to clean up after.
Poker tournaments, strippers and raw meat are all enticing, but entail risks from gambling opponents, church ladies, and FDA inspectors (in no particular order). It has been scientifically proven that dueling pianos and karaoke nights draw the best crowds, but on their own they rank too low to succeed.
The "Crazy 88's" show combines the best of Karaoke, the fun of a dueling pianos show, occasional comedy, borderline talent competition worthy of any American Idol elimination round, and much, much more.