I still think based off of how much it cost versus how much it earned, "The Adventures of Pluto Nash" will go down as the biggest bust of all time. A hundred million to make and it barely earned over seven million? That's atrocious. Even some of the recent bombs at least made over a hundred million dollars at the box office, which is respectable, even if it cost a lot to make.
As far as Dune goes, I read the book my freshman year of high school while I was out sick with mono. One of my all time favorite books (Never read any of the other ones; I kinda didn't want to risk ruining how much I enjoyed the first). I still think the movie was bad. The voice guns, the body shields, and the way everyone was whispering everything was really annoying. Also, the special effects were fucking awful, which didn't make any sense to me because it came out after the Star Wars movies. It did have Patrick Stewart in it, which is a plus.