Biggest? There are so many to choose from. They say "if you're not failing enough, you're not trying enough". Then I guess I try alot. I like taking reasonable risks so the projects i like to take on usually have something about them that is new or untried. But how do you measure failure? "Mission:Space" had an entirely new ride system to deliver the sustained G forces of liftoff, but it was too much for some people and that hurt attendance. Failure can be financial or creative (or both!). Main Street in DLP to me was a creative success trapped in a fiscal disaster. "Knott's Soap Box Racers" Ride to me was a creative embarrassment but it was hugely successful in ridership (120% of the gate) and actually drove attendance that year.
"Six Flags Power Plant" in Baltimore Maryland was a huge flop on pretty much both levels. (thread on it here, there is a Ryman painting of it too!
http://www.greatadventurehistory.com/Forums/index.php?showtopic=1395)
I was hired by Gary Goddard Productions from Knott's to design a walk thru Attraction based on an existing premise (exploring the laboratory of victorian master inventor Phineas Flagg) and did so. The premise we worked from was flawed from the outset (school groups thought it was true!) and it was executed ambitiously from a meager budget so nothing worked reliably, so it failed both commercially and creatively. Ouch. Looked great but "why for?". Good early career lesson.
The "Steampunk" design of the elements themselves was good but no one "got it" and it was a huge disaster. The good news was that Tony Baxter saw it's merits, liked my "Discovery Bay" style design, and I got hired at WED as a result, so in a personal way it served as a successful audition! That "flop" paid off in a Disney career! Thanks to Tony having the insight to separate a flawed idea from the hard work and design quality.
